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Causes of atheism

2015-01-28T00:36:51Z

ScKinney:

[[Image:Stalin-140508 27880t.jpg|right|225px|thumb|In 1932, the brutal atheist dictator and [[militant atheism|militant atheist]] [[Joseph Stalin]] penned a repressive “Five Year Plan of Atheism”.<ref>[http://winteryknight.wordpress.com/2014/02/27/was-stalin-an-atheist-is-atheism-or-communism-responsible-for-mass-murders/ Was Stalin an atheist? Is atheism or communism responsible for mass murders?]</ref> See also: [[State atheism]] and [[Atheism and mass murder]] ]]
There are a number of reasonable explanations for the '''causes of [[atheism]]''':

1. '''Moral depravity:''' The history of the atheist community and various studies concerning the atheist community point to moral depravity [[Atheism and morality| being a causal factor]] for atheism.<ref>
*[http://www.apologetics.com/index.php?option=com_content&view=article&id=469:the-causes-of-atheism&catid=96:bonus-content&Itemid=80 The causes of atheism]
*[http://www.str.org/site/News2?page=NewsArticle&id=5527 The Real Murderers: Atheism or Christianity?]
*[http://abcnews.go.com/2020/Story?id=2682730&page=2 Who Gives and Who Doesn't? - ABC News]
*[http://findarticles.com/p/articles/mi_qa3647/is_200310/ai_n9340592/ Religious faith and charitable giving, Policy Review , Oct-Dec 2003, p.2.]
*[http://www.barna.org/barna-update/article/5-barna-update/58-practical-outcomes-replace-biblical-principles-as-the-moral-standard Practical Outcomes Replace Biblical Principles As the Moral Standard]
*[http://www.barna.org/barna-update/article/12-faithspirituality/102-atheists-and-agnostics-take-aim-at-christians Atheists and Agnostics Take Aim at Christians]</ref>

See: [[Moral failures of the atheist community]]

In addition, there is the historical matter of deceit being used in a major way to propagate atheism from the time of [[Charles Darwin]] onward (see: [[Atheism and deception]]).

The [[Bible]] indicates that atheists are morally depraved. The psalmist [[David]] declared:
"The fool has said in his heart, 'There is no God.' They are corrupt, they have done abominable works, there is none that doeth good." — [[Psalms]] 14:1 ([[King James Bible|KJV]]). The prophet [[Jeremiah]] wrote: "The heart is deceitful above all things, and desperately wicked: who can know it?" - Jeremiah 17:9 (KJV)

[[Francis Thompson]] wrote: "Maybe the atheist cannot find [[God]] for the same reason a thief cannot find a policeman."

Moral depravity is certainly one of the prime causes of atheism.

See also: [[Atheism and morality]] and [[Atheism and moral intelligence]] and [[Atheism and hedonism]] and [[Atheist hypocrisy]]

'''2.''' '''Hatred towards God.''' Angry and bitter and attacks on Christianity and Christians by atheists are most often due to hatred towards [[Jesus Christ]] and the Bible.<ref>[http://creation.com/chris-hitchens-dies Christopher Hitchens: Staring Death in the Face And the difference that Biblical Creation makes!]</ref><ref>[http://www.truefreethinker.com/articles/argument-atheism-immaturity The Argument for Atheism from Immaturity]</ref> See also: [[Atheism and hatred of God]]

'''3.''' '''Atheistic upbringing'''. However, according to recent research by the Pew Forum on Religion and Public Life, in the [[United States]], a majority of those surveyed who were raised in atheist or [[agnosticism|agnostic]] households, or where there was no specific religious attachment, later chose to join a religious faith.<ref>http://www.theaustralian.com.au/news/opinion/defectors-to-faith-mark-a-growing-trend/story-e6frg7ko-1225710667095</ref><ref>http://pewresearch.org/pubs/1204/religion-changes-affiliations-survey</ref> A notable example, of a person raised in a atheistic household who later became a [[Christian]] is William J. Murray. Mr. Murray was raised by [[Madalyn Murray O'Hair]] who founded the organization American Atheists.

In addition, Christianity is experiencing rapid growth in atheistic [[communism|communist]] China and has experienced rapid growth in former communist countries. <ref>http://www.millennialstar.org/christianity-exploding-in-china/</ref><ref>http://www.cbn.com/cbnnews/shows/cwn/2008/August/Christianity-Growing-in-China-/</ref><ref>http://www.nytimes.com/2005/07/03/international/europe/03romania.html</ref>

'''4.''' '''Poor relationship with father/mother/parents:'''

The ''Cambridge Companion to Atheism'' which was edited by the atheist [[philosophy|philosopher]] [[Michael Martin]] declared:
{{cquote|Continuity and discontinuity in any identity may be a function of interpersonal networks, especially involving intimate relations. Apostasy and conversion can both be seen as a rejection of parental identity and parental beliefs. It “might well be symptomatic of familial strain and dissociation... apostasy is to be viewed as a form of rebellion against parents” (Caplovitz and Sherrow, 1977:50).<ref>''The Cambridge Companion to Atheism'', edited by [[Michael Martin]], page 302, published in 2006</ref>}}
[[Image:DrVitz.jpg|thumbnail|225px|right|[[Ex-atheists|Ex-atheist]] [[Paul Vitz]] ]]
A troubled/non-existent relationship with a father can influence a person to become an atheist.<ref>http://www.leaderu.com/truth/1truth12.html</ref> Dr. [[Paul Vitz]] wrote a book entitled ''Faith of the Fatherless'' in which he points out that after studying the lives of more than a dozen leading atheists he found that a large majority of them had a father who was present but weak, present but abusive, or absent.<ref>Vitz, Paul, [http://www.columbia.edu/cu/augustine/arch/vitz.txt The Psychology of Atheism], September 24, 1997 (lecture notes taken by an audience member).</ref><ref>Anders, Kerby, [http://www.probe.org/content/view/36/91/ Atheists and Their Fathers] (Probe Ministries)</ref> Dr. Vitz also examined the lives of prominent theists who were contemporaneous to their atheist counterparts and from the same culture and in every instance these prominent theists had a good relationship with his father.<ref>http://www.columbia.edu/cu/augustine/arch/vitz.txt</ref> Dr. Vitz has also stated other common factors he observed in the leading atheists he profiled: they were all intelligent and arrogant.<ref>http://www.columbia.edu/cu/augustine/arch/vitz.txt</ref>

The book ''Atheist Persona: Causes and Consequences'' by John J. Pasquini, Th.D. indicates that many of the prominent atheists (and prominent [[practical atheism|practical atheists]]) who had dysfunctional/absent fathers that he lists in his book also had dysfunctional/absent mothers.<ref>Atheist Persona: Causes and Consequences by John J. Pasquini, 2014, University Press of America, page 3</ref> See also: [[Atheism and poor relationships with parents]] and [[Irreligion and domestic violence]]

'''5.''' '''Pride/Rebellion:''' Atheism stems from a choice to ignore the reality of God's existence <ref>"For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who suppress the truth in unrighteousness, because what may be known of God is manifest in them, for God has shown it to them. For since the creation of the world His invisible attributes are clearly seen, being understood by the things that are made, even His eternal power and Godhead, so that they are without excuse, For the invisible things of him from the creation of the world are clearly seen, being understood by the things that are made, [even] his eternal power and Godhead; so that they are without excuse..." —{{Bible ref|Romans|1|19-20|version=NKJV}}</ref><ref>[http://www.atheism-analyzed.net/Atheist%20Talking%20Points%20Rebellion.htm Atheist talking points]</ref> [[Dinesh D'Souza]] declared: "Look at [[Satan]]'s reason for rebelling against God. It's not that he doesn't recognize that God is greater than he is. He does. It's just that he doesn't want to play by anybody else's rules. This idea that it is better to reign in [[hell]] than to serve in [[heaven]] is Satan's motto, and it turns out that this is also the motto of contemporary atheists such as [[Christopher Hitchens]]." <ref>[http://www.salvomag.com/new/articles/salvo7/7segelstein.php Salvomag.com The Apologist, An Interview with Dinesh D'Souza, Author of What's So Great About Christianity by Marcia Segelstein]</ref> See also: [[Atheism and arrogance]]

'''6.''' '''Immaturity.'''<ref>[http://voxday.blogspot.com/2011/01/answering-atheists-question.html Answering an atheist's question]</ref><ref>[http://www.truefreethinker.com/articles/argument-atheism-immaturity The Argument for Atheism from Immaturity]</ref><ref>[http://www.christianpost.com/news/study-atheists-have-lowest-retention-rate-compared-to-religious-groups-78029/ Study: Atheists Have Lowest 'Retention Rate' Compared to Religious Groups</ref><ref>[http://news.uchicago.edu/article/2012/04/18/belief-god-rises-age-even-atheist-nations Belief in God rises with age, even in atheist nations]</ref> In 2012, a [[Georgetown University]] study was published indicating that only about 30 percent of those who grow up in an atheist household in the United States remain atheists as adults. <ref>[http://www.christianpost.com/news/study-atheists-have-lowest-retention-rate-compared-to-religious-groups-78029/ Study: Atheists Have Lowest 'Retention Rate' Compared to Religious Groups</ref> A 2012 study by the General Social Survey of the social science research organization NORC at the University of Chicago found that belief in God rises with age, even in atheistic nations.<ref>[http://news.uchicago.edu/article/2012/04/18/belief-god-rises-age-even-atheist-nations Belief in God rises with age, even in atheist nations]</ref> See: [[Atheism has a lower retention rate compared to other worldviews]] and [[Atheism and immaturity]]
[[File:Larry Flynt Wheelchair.jpg|thumbnail|200px|right|The [[pornography|pornographer]] [[Larry Flynt]] is an atheist.<ref>Flynt writes, "I have left my religious conversion behind and settled into a comfortable state of atheism": see the epilogue of Flynt and Ross</ref><ref>"I am not saying he don't believe in God. I am just saying I don't believe in God. That puts me at odds with him." ''[http://www.cnn.com/SHOWBIZ/9701/11/falwell.v.flynt/lkl.00.html Larry King Live]'', January 10, 1996</ref> See: [[Atheism and hedonism]] 
(photo obtained from [http://commons.wikimedia.org/wiki/File:Larry_Flynt_Wheelchair.jpg Wikimedia Commons], see: [http://creativecommons.org/licenses/by-sa/3.0/deed.en license agreement]) ]]
[[Vox Day]] writes about immaturity being a causal factor for atheism: "the age at which most people become atheists indicates that it is almost never an intellectual decision, but an emotional one. (This is why most self-identified atheists are angry, bitter, and immature. The anger, bitterness, and immaturity are usually the cause of the atheism, they are not, as many Christians erroneously suppose, the effects).<ref>[Answering an atheist's question]</ref>

'''7.''' '''Anger and bitterness.'''<ref>[http://voxday.blogspot.com/2011/01/answering-atheists-question.html Answering an atheist's question]</ref> See: [[Atheism and anger]] and [[Militant atheism]]

'''8.''' '''[[Hedonism]]'''.<ref>[http://creation.com/atheist-god-hate Why do atheists hate God?]</ref> The [[Saint Paul|Apostle Paul]] wrote that in the [[end times]], men would be lovers of pleasure rather than lovers of God (2 Timothy 3:1-4).

The infamous [[pornography|pornographers]] [[Hugh Hefner]] and [[Larry Flynt]] are both [[Atheism|atheists]].<ref>[http://www.salon.com/2013/02/23/10_celebs_you_didnt_know_were_atheists_partner/ 10 celebs you didn't know were atheists], ''Salon'' 2-23-2010</ref> <ref>Flynt writes, "I have left my religious conversion behind and settled into a comfortable state of atheism": see the epilogue of Flynt and Ross</ref><ref>"I am not saying he don't believe in God. I am just saying I don't believe in God. That puts me at odds with him." ''[http://www.cnn.com/SHOWBIZ/9701/11/falwell.v.flynt/lkl.00.html Larry King Live]'', January 10, 1996</ref> See: [[Atheism and hedonism]]

'''9.''' '''Naiveté/Gullibility''': Many atheists have embraced a number of far fetched, unworkable, and errant notions and ideologies such as [[communism]], [[Origin of Life|abiogenesis]], and [[evolution]] despite abundant evidence of their falsity. See: [[Rebuttals to atheist arguments]] and [[Causes of evolutionary belief]] and [[Atheist cults]]

'''10.''' '''Irrational thinking''': As noted earlier, a comprehensive study by Baylor University found that the irreligious and the members of more liberal Protestant denominations, tend to be much more likely to believe in the paranormal and in [[pseudoscience]] than evangelical Christians.<ref>http://online.wsj.com/article/SB122178219865054585.html</ref> Also, as noted above, a 1980 study published in the magazine ''Skeptical Inquirer'' found irreligious college students to be by far the most likely to embrace paranormal beliefs, while born again Christian college students were found to be the least likely.<ref>http://online.wsj.com/article/SB122178219865054585.html</ref> See: [[Atheism and irrationality]]

'''11.''' '''Superficiality:''' Noted [[ex-atheists|ex-atheist]] and psychologist Dr. [[Paul Vitz]] has stated that he had superficial reasons for becoming an atheist such as the desire to be accepted by his [[Stanford University]] professors who were united in disbelief regarding God.<ref>http://www.columbia.edu/cu/augustine/arch/vitz.txt</ref>
[[File:Evolution.jpg|alt=evolution darwin theory|right|thumb|235px|Late in [[Charles Darwin|Charles Darwin's]] life, Darwin told the Duke of Argyll that he frequently had overwhelming thoughts that the natural world was the [[Intelligent design|result of design]].<ref>http://plato.stanford.edu/entries/teleological-arguments/notes.html</ref> In a letter to [[Asa Gray]], Darwin confided: "...I am quite conscious that my speculations run quite beyond the bounds of true [[science]]."<ref>http://www.darwinproject.ac.uk/entry-2109</ref> See: [[Irreligion and superstition]] and [http://conservapedia.com/Charles_Darwin#Religious_Views_of_Charles_Darwin Religious views of Charles Darwin] ]]

'''12.''' '''Error:''' Some argue that atheism partly stems from a failure to fairly and judiciously consider the facts <ref>"A young man who wishes to remain a sound Atheist cannot be too careful of his reading. There are traps everywhere--'Bibles laid open, millions of surprises,' as Herbert says, 'fine nets and stratagems.' God is, if I may say it, very unscrupulous." -- C.S. Lewis, ''Surprised by Joy''.</ref>

'''13.''' '''State churches:''' In regards to the causes of atheism, rates of atheism are much higher in countries with a state sanctioned religion (such as many European countries), and lower in states without a sanctioned religion (such as the United States). Some argue this is because state churches become bloated, corrupt, and/or out of touch with the religious intuitions of the population, while churches independent of the state are leaner and more adaptable. It is important to distinguish "state-sanctioned churches," where participation is voluntary, from "state-mandated churches" (such as Saudi Arabia) with much lower atheism rates because publicly admitted atheism is punishable by death. <ref>http://online.wsj.com/article/SB118434936941966055.html?mod=googlenews_wsj</ref>

'''14.''' '''Decline of family in a culture''' - Mary Eberstadt, a research fellow at [[Stanford University]]’s [[Hoover Institution]], found the decline of [[family values]] leads to a rise in secularization.<ref>[http://www.rightwingnews.com/interviews/an-interview-with-mary-eberstadt-on-her-new-book-how-the-west-really-lost-god-a-new-theory-of-secularization/ An Interview With Mary Eberstadt On Her New Book “How the West Really Lost God: A New Theory of Secularization]</ref>

'''15.''' '''[[Socialism]]''' <ref>[http://questionevolution.blogspot.com/2012/07/does-atheism-thrive-on-economic.html Does atheism thrive on economic prosperity? Does religion prosper when people are desperate and ignorant?]</ref> and [[communism|communist]]/leftist governments. See also: [[Atheism and politics]]

According to the [[University of Cambridge]], historically, the "most notable spread of atheism was achieved through the success of the 1917 Russian Revolution, which brought the [[Marxism-Leninism|Marxist-Leninists]] to power."<ref name="Marxism-Leninsim">{{cite web|url = http://www.investigatingatheism.info/marxism.html|title =Marxism|publisher = [[University of Cambridge]]|quote=The most notable spread of atheism was achieved through the success of the 1917 Russian Revolution, which brought the Marxist-Leninists to power. For the first time in history, atheism thus became the official ideology of a state.|year=2008|accessdate = 2011–03–15}}</ref> Vitalij Lazarʹevič Ginzburg, a Soviet physicist, wrote that the "[[Bolshevik]] communists were not merely atheists but, according to [[Lenin]]'s terminology, [[militant atheist]]s."<ref name="Lenin & militant atheism">{{cite web|url = http://books.google.com/books?id=ufC9Ar8iuDcC&pg=PA161&dq=The+Bolshevik+communists+were+not+merely+atheists+but,+according+to+Lenin%27s+terminology,+militant+atheists.&hl=en&sa=X&ei=1oFUUdj6PIiK0QGvq4CAAw&redir_esc=y#v=onepage&q=The%20Bolshevik%20communists%20were%20not%20merely%20atheists%20but%2C%20according%20to%20Lenin's%20terminology%2C%20militant%20atheists.&f=false|title =On Superconductivity and Superfluidity: A Scientific Autobiography |author=Vitalij Lazarʹevič Ginzburg|publisher = Springer Science+Business Media|year=2009|quote=The Bolshevik communists were not merely atheists but, according to Lenin's terminology, militant atheists.|accessdate = 2011–03–15}}</ref> However, prior to this, the [[Reign of Terror]] of the [[French Revolution]] established an [[atheist state]], with the official ideology being the [[Cult of Reason]]; during this time thousands of believers were suppressed and executed by the [[guillotine]].<ref name="Guillotine">{{cite web|url = http://books.google.com/books?id=bf3m7IVAa9gC&pg=PA461&dq=France+atheism+guillotine++Christians+executed&hl=en&sa=X&ei=l4lUUaTRBufG0QGe0IHACA&redir_esc=y#v=onepage&q=France%20atheism%20guillotine%20%20Christians%20executed&f=false|title =Christianity|author=James Adair|publisher = JBE Online Books|year=2007|quote=Although the Civil Constitution called for religious liberty, which was extended to Jews as well as Christians, many revolutionaries pushed for the establishment of a new state religion, either the Cult of Reason (atheists) or the Cult of the Supreme Being (Deists). Changes toAlthough the Civil Constitution called for religious liberty, which was extended to Jews as well as Christians, many revolutionaries pushed for the establishment of a new state religion, either the Cult of Reason (atheists) or the Cult of the Supreme Being (Deists). Changes to the calendar eliminated references to Christian holidays, and even the ancient seven-day week, and a ist of officially recognized saints included such famous thinkers such as Socrates, Jesus, Marcus Aurelius, and Jean-Jacques Rosseau. A period of political persecution, often with religious overtones, broke out, known as the Reign of Teror. Thousands of people were executed by the guillotine, including many of the original leaders of the French Revolution.|page=461|accessdate = 2011–03–15}}</ref><ref name="France">{{cite web|url = http://books.google.com/books?id=9WkBAAAAYAAJ&pg=PA105&dq=Reign+of+Terror+atheism&hl=en&sa=X&ei=HoRUUcD0NeXX0gGNo4HIDQ&redir_esc=y#v=onepage&q=Reign%20of%20Terror%20atheism&f=false|title =Memoirs of the reign of George III. to the session of parliament ending A.D. 1793, Volume 5|page=105|author=William Belsham|publisher = G.G. & J. Robinson|year=1801|quote=Reign of this portentous period, it has been eloquently tenor, and energetically observed, " that the reign of atheism in France was avowed the reign of terror. In the full madness of their career, in the highest climax of their horrors, they shut up the temples of God, abolished His worship, and proclaimed death to be an eternal sleep:-in the very centre of Christendom, Revelation underwent a total eclipse, while atheism, performing on a darkened theatre its strange and fearful tragedy, confounded the first elements of society, blended every age, rank, and sex ,indiscriminate proscription and massacre, and convulsed all Europe to its centre, that the imperishable memorial of these events might teach the last generations of mankind to consider religion as the pillar of society, the parent of social order, and the safe-guard of nations." It is wonderful that, amid the horrors of this dismal period, while "the death dance of democratic revolution" was still in rapid movement, among the tears of affliction, and the cries of despair, "the masque, the song, the theatric scene, the buffoon laughter, went on as regularly as in the gay hour of festive peace."|accessdate = 2011–03–15}}</ref><ref name="Reign of Terror">{{cite web|url = http://books.google.com/books?id=Tt5rqiCP1p8C&pg=PA57&dq=Reign+of+Terror+atheism&hl=en&sa=X&ei=HoRUUcD0NeXX0gGNo4HIDQ&redir_esc=y#v=onepage&q=Reign%20of%20Terror%20atheism&f=false|title =Christianity, Islam, and Atheism: The Struggle for the Soul of the West|author=William Kilpatrick|publisher = Ignatius Press|year=2012|quote=Actually, it's helpful to think in terms of two Enlightenments: the Enlightenment that cut itself off from God. The former led to the American Revolution, the Declaration of Independence, the abolition of slavery, and the civil rights movement. The latter led to the French Revolution, the Reign of Terror, the suppression of church by state, and the godless philosophies of Marx and Nietzsche and their offspring-National Socialism and communism. More recently the abandonment of God has led to the regime of cultural relativism that regards rights as arbitrary constructions. It's this second Enlightenment tradition that Cardinal Ratzinger referred to when he wrote, "The radical detachment of the Enlightenment philosophy from its roots ultimately leads it to dispense with man." Actually this transition happened no "ultimately" but almost immediately. The first instance occurred when Enlightenment worship of abstract "reason" and "liberty" degenearated quickly into the mass murders committed during the antireligious Reign of Terror in France. "Liberty, what crimes are committed in your name", said Madam Rolande as she faced the statue of Liberty in the Place de la Revolution movements before her death at the guillotine. She was one of the early victims of a succession of secular systems based on rootless notions of "liberty", "equality", and "reason". As many historians have pointed out, the atheist regimes of modern times are guilty of far more crimes than any committed in the name of religion. Communist governments alone were guilty of more than one hundred million murders, most of them committed against their own people.|accessdate = 2011–03–15}}</ref>

The atheism in [[communism|communist]] regimes has been and continues to be [[militant atheism]] and various acts of repression including the razing of thousands of religious buildings and the killing, imprisoning, and oppression of religious leaders and believers.<ref>
*[http://www.cnn.com/2011/WORLD/asiapcf/04/28/china.church.crackdown/index.html?hpt=T2 Underground Christians fear China crackdown]
*[http://books.google.com/books?visbn=0300103220&id=ChRk43tVxTwC&pg=PA165&lpg=PA165&ots=ICIxg28Jud&dq=a+century+of+violence+in+soviet+russia+the+Russian+Orthodox+clergy&ie=ISO-8859-1&sig=C9k9Hr7Vn222WCHf_1iSJOHVsgo#v=onepage&q=&f=false A Century of Violence in Soviet Russia]
*[http://www.orthodoxinfo.com/ecumenism/frroman1.aspx On Compromise in the Hierarchy During the Communist Yoke]
*[http://www.nysun.com/article/23082?page_no=1 Korean Reds Targeting Christians]
*[http://www.newsmax.com/archives/articles/2003/5/7/120250.shtml North Korean and Chinese Atrocities Against Christians Worsen]
*[http://www.worldnetdaily.com/news/article.asp?ARTICLE_ID=35818 China sends Bible owners to labor camp]
*[http://theworldnow.wordpress.com/tag/around-the-world/asia/china/ China: Christians Tortured While Under Arrest]</ref>

Currently, Communist [[China]], the world's largest country in terms of adherents to atheism, is seeing an explosive growth of Christianity. See: [[Global Christianity]] and [[Global atheism]] and [[Atheism has a lower retention rate compared to other worldviews]]

'''16.''' '''Self-deception'''<ref>[http://creation.com/atheism Atheism - Satanic deception and self-deception]</ref>

'''17.''' '''[[Satan|Satanic]] deception''' <ref>[http://creation.com/atheism Atheism - Satanic deception and self-deception]</ref> (''see also'': [[Atheism and satanic deception]] )

'''18.''' '''Division in religion''': According to Sir [[Francis Bacon]], atheism is caused by "divisions in religion, if they be many; for any one main division addeth zeal to both sides, but many divisions introduce atheism."<ref>[http://www.bartleby.com/3/1/16.html Francis Bacon, Of atheism - essay]</ref>
[[Image:Jhcfju6.jpg|right|thumb|200px|[[C. S. Lewis]], photographed in 1947.]]
'''19.''' '''Ignorance.'''

The [[ex-atheists|ex-atheist]] [[C.S. Lewis]] wrote: "In reading [[G.K. Chesterton|Chesterton]], as in reading [[George MacDonald|MacDonald]], I did not know what I was letting myself in for. A young man who wishes to remain a sound Atheist cannot be too careful of his reading. There are traps everywhere--"Bibles laid open, millions of surprises," as Herbert says, "fine nets and stratgems." Sir Francis Bacon wrote: "A little philosophy inclineth man's mind to atheism, but depth in philosophy bringeth men's minds about to religion." See also: [[Christian apologetics]]

Individuals such as Calvin Smith of [[Creation Ministries International]] have reported leaving atheism after finding out the falsehood of evolutionary pseudoscience and the evidence for [[Bible|biblical]] [[creation]].<ref>[http://creation.com/calvin-smith Calvin Smith - short bio]</ref>

The ex-atheist [[Lee Strobel]] in his book "The Case for Christ" indicates how he used his journalist skills and legal training to discover the truth of the [[resurrection of Jesus Christ]]. See also: [[Christian legal apologetics]]

For more information see: [[Atheism and education]]

'''20.''' '''Indoctrination and ease of life''': Francis Bacon argued that atheism was partly caused by:"Learned times, specially with peace and prosperity; for troubles and adversities do more bow men’s minds to religion."<ref>[http://www.bartleby.com/3/1/16.html Francis Bacon, Of atheism - essay]</ref> See also: [[Atheist indoctrination]] and [[Atheism and economics]]

In addition, [[Judaism|Jewish]] columnist [[Dennis Prager]] has stated that a causal factor of atheism is the "secular indoctrination of a generation."<ref>http://www.worldnetdaily.com/index.php?pageId=43734</ref> Prager stated that "From elementary school through graduate school, only one way of looking at the world – the secular – is presented. The typical individual in the [[Western World|Western world]] receives as secular an indoctrination as the typical European received a religious one in the [[Middle Ages]]." <ref>http://www.worldnetdaily.com/index.php?pageId=4373</ref> In 2013, an study found that academia was less likely to hire evangelical Christians due to discriminatory attitudes.<ref>[http://townhall.com/columnists/rachelalexander/2013/06/10/suspicions-confirmed-academia-shutting-out-conservative-professors-n1616406/page/full Suspicions Confirmed: Academia Shutting Out Conservative Professors]</ref>

[[Dinesh D'Souza]] has pointed out that atheists have focused considerable efforts on the public schools in order to indoctrinate young people into atheistic beliefs.<ref>[http://townhall.com/columnists/dineshdsouza/2007/10/22/the_atheist_indoctrination_project/page/full The atheist indoctrination project]</ref> In addition, in communist countries (such as the former Soviet Union) atheistic indoctrination occurred in the educational system through such venues as schools, atheist museums, and clubs (see also: [[Militant atheism]]).<ref>[http://books.google.com/books?id=BGJtDwJ7aPwC&pg=PA325&lpg=PA325&dq=atheistic+upbringing+and+atheism&source=bl&ots=eQlq1dZfMj&sig=Xm__18YZpV5L0O8VVzgAc9YiSCc&hl=en&ei=yOy1S76CGcWAlAedg5FR&sa=X&oi=book_result&ct=result&resnum=5&ved=0CBIQ6AEwBDgK#v=onepage&q=atheistic%20upbringing%20and%20atheism&f=false Marxist-Leninist 'Scientific Atheism' and the Study of Religion and Atheism By James Thrower, page 325]</ref><ref>[http://www.lituanus.org/1963/63_1_01.htm Communism's Struggle with Religion in Lithuania]</ref> Atheists and secularists rarely point out that universities such as [[Harvard]], [[Princeton]], [[Oxford]], [[Cambridge]], and many others were founded by Christians.<ref>http://www.answersingenesis.org/articles/am/v2/n3/harvard-yale-princeton-oxford-once-christian</ref><ref>http://www.tysknews.com/Depts/Educate/history_part3.htm</ref>

See also: [http://questionevolution.blogspot.com/2012/07/does-atheism-thrive-on-economic.html Does atheism thrive on economic prosperity and religion prosper when people are desperate and ignorant?]

'''21.''' '''Negative experiences with [[theism|theists]]'''

'''22.''' '''[[Materialism|Materialist]] [[pseudoscience]].''' (See: [[Evolution]] and [[Origin of Life|Abiogenesis]]). Countries with higher rates of [[Darwinism]] also have higher rates of atheism.<ref>[http://www.adherents.com/largecom/com_atheist.html Atheist populations in various countries]</ref><ref>[http://news.nationalgeographic.com/news/bigphotos/21329204.html Belief in evolution in various countries]</ref> Biblical creationists, such as advocates of the [[Question evolution! campaign]], assert that evolutionism is an ideological "air supply of atheism" and that reducing Darwinism will reduce the prevalence of atheism. <ref>[http://questionevolution.blogspot.com/2011/12/cutting-off-air-supply-of-atheism.html Cutting off the air supply of atheism]</ref>

'''23.''' '''[[Scientism]]:''' ''Science has in many ways become a new god''.<ref>[http://creation.com/the-religion-of-scientism-m-shallis The religion of scientism]</ref><ref>[http://www.saintsandsceptics.org/dawkins-dilbert-and-the-illogical-scientists/ Dawkins, Dilbert and the Illogical Scientists]</ref><ref>[http://www.religiontoday.com/news/exposing-the-religion-of-scientism-11598780.html Exposing the religion of scientism]</ref> Scientism is self-refuting. [[William Lane Craig]] wrote: "Scientism tells us that we should not believe any proposition that cannot be scientifically proven. But what about that very proposition itself? It cannot itself be scientifically proven."<ref>[http://www.reasonablefaith.org/is-scientism-self-refuting Is scientism self-refuting?]</ref> See also: [[Atheism and naturalistic intelligence]]

'''24.''' Pursuit of prestige within secular circles.<ref>Amongst the most elite in terms of prestige within the scientific community – the Nobel Laureates and the U. S. Academy of Sciences – the percent of atheists is the highest, around 93%. Part of this is due to discrimination against [[Creation science|creation scientists]]. See: [[Suppression of alternatives to evolution]]. In addition, there is discrimination against religious conservatives in academia (see: [[Atheist indoctrination]]). Biet-Hallahmi, author of ''Atheism, A Psychological Profile'', in ''The Cambridge Companion to Atheism'', wrote, “…what these individuals [the most elite] had, in addition to their creativity and high intelligence, was a strong wish to create distance between themselves and their parents.” Dr. [[Paul Vitz]], author of'' Faith of Fatherless'', indicated that one of the common factors he observed in the leading atheists he profiled: they were all intelligent and arrogant. See also: [[Atheism and arrogance]] and [[Atheism and intelligence]]</ref>

'''25.''' '''Intellectual cowardice.''' See: [[Atheism and cowardice]]

'''26.''' In cultures not receptive to atheism, atheists appear to be more likely to be social outcasts (see: [[Atheism and social outcasts]]).

'''27.''' [[Video Games]] are a leading cause of atheism.

== Errant notion that atheism is the result of higher intelligence ==

''See also:'' [[Atheism and intelligence]] and [[Atheism and education]] and [[Rebuttals to atheist arguments]]

A common errant notions among atheists is the mistaken belief that atheism is the result of higher intelligence. This belief often the result of excessive pride, the foolish nature of atheists [[Atheism and deception|and self-deception]]. For more information, please see: [[Atheism and intelligence]].

Also, due the lack of evidence for atheism and the [[Christian apologetics|great amount of evidence]] for Christianity, atheism is not a respectable intellectual position. For example, God's [[creation]] plainly points to the existence of God <ref>[http://creation.com/creation-answers Creation vs. evolution]</ref> (see also: [[Atheism has a lower retention rate compared to other worldviews]]).

==See Also==

*[[Resources for leaving atheism and becoming a Christian]]
*[[Christian apologetics|Evidence for Christianity]]
*[[Rebuttals to atheist arguments]]

Other articles relating to atheism:

*[[Atheism and deception]]
*[[Atheism and satanic deception]]
*[[Atheist hypocrisy]]
*[[Atheist mindset]]
*[[Atheism, pederasty and NAMBLA]]
*[[Atheism and bestiality]]
*[[Atheist factions]]
*[[Evolution]]
*[[Atheism and Mass Murder]]
*[[Atheism and Debate]]
*[[Atheism and charity]]
*[[There Are No Atheists In Foxholes]]

== Books on the causes of atheism ==

''See also:'' [[Books on the causes of atheism]]

*''Atheist Persona: Causes and Consequences'' by John J. Pasquini, Th.D, Rowman & Littlefield Publishers, Published: April 15, 2014, ISBN-10: 0761863311; ISBN-13: 978-0761863311[http://books.google.com/books/about/Atheist_Persona.html?id=TaTsnQEACAAJ]

*[http://books.google.com/books?id=IeUIAAAACAAJ ''Faith of the Fatherless: The Psychology of Atheism''] by [[Paul Vitz]] (Spence Publishing Company, 1999)

*''Immorality and pride, the great causes of atheism a sermon preach'd at the cathedral-church of St. Paul, January the 8th 1697/8 : the first of the lecture for that year, founded by the Honourable [[Robert Boyle]], Esq.'' / by John Harris, Publisher: BiblioBazaar, 2011 ISBN 1240832273, 9781240832279 [http://books.google.com/books/about/Immorality_and_Pride_the_Great_Causes_of.html?id=RxpNYgEACAAJ]

* ''[http://www.voxday.net/mart/TIA_free.pdf The Irrational atheist]: Dissecting the Unholy Trinity of Dawkins, Harris, and Hitchens by [[Vox Day]], Benbella Books, Dallas, TX, 2008'' , ISBN-10: 1933771364; ISBN-13: 978-1933771366

==External Links==

*[http://www.apologetics.com/index.php?option=com_content&view=article&id=469:the-causes-of-atheism&catid=96:bonus-content&Itemid=80 The causes of atheism] by James Spiegel
*[http://questionevolution.blogspot.com/2012/03/why-is-evolution-is-pushed-in-america.html Why is evolution pushed by dogmatic evolutionists?]
*[http://questionevolution.blogspot.com/2012/07/does-atheism-thrive-on-economic.html Does atheism thrive on economic prosperity and religion prosper when people are desperate and ignorant?]
*[http://voxday.blogspot.com/2011/11/mailvox-its-not-about-interlocutor.html Vox Day on why some people choose to be atheists]
*[http://www.youtube.com/watch?v=imuaiRO5mSQ Christians Give more to Charity than Atheists] by Dr. [[William Lane Craig]] - [[YouTube]] video
*[http://veritas.org/media/talks/344 Psychology of Atheism - Audio File]

== Notes ==
{{reflist|2}}
[[Category:Atheism]]

Enceladus

2015-01-28T00:25:37Z

ScKinney: /* Surface */

{{Planet
|image=Enceladus north pole.jpg
|caption=North pole region of Enceladus, by Cassini
|date=August 28, 1789<ref name=usgs>"[http://planetarynames.wr.usgs.gov/append7.html Gazetteer of Planetary Nomenclature: Planetary Body Names and Discoverers]." US Geological Survey, Jennifer Blue, ed. March 31, 2008. Accessed April 17, 2008.</ref>
|discname=William Herschel<ref name=usgs/><ref name=Hamilton>Hamilton, Calvin J. "[http://solarviews.com/eng/enceladus.htm Entry for Enceladus]." ''Views of the Solar System'', 2001. Accessed June 17, 2008.</ref>
|origname=Giant killed in action in the Titan-Olympian War<ref name=usgs/>
|primary=Saturn
|order=9
|periapsis=236,949 km<ref name=calc>Calculated</ref>
|apoapsis=239,091 km<ref name=calc/>
|semimajor=238,020 km<ref name=saturnsatfact>Williams, David R. "[http://nssdc.gsfc.nasa.gov/planetary/factsheet/saturniansatfact.html Saturnian Satellite Fact Sheet]." National Space Science Data Center, [[National Aeronautics and Space Administration|NASA]], November 23, 2007. Accessed June 4, 2008.</ref><ref name=arval>"[http://www.oarval.org/ClasSaten.htm Classic Satellites of the Solar System]." ''Observatorio ARVAL'', April 15, 2007. Accessed June 12, 2008.</ref>
|eccentricity=0.0045<ref name=saturnsatfact/>
|sidereal=1.370218 da<ref name=saturnsatfact/>
|orbitspeed=12.64 km/s<ref name=saturnsatfact/>
|inclination=0.00°<ref name=saturnsatfact/>
|siderealday=1.370218 da<ref name=saturnsatfact/>
|rotatespeed=0.01339 km/s<ref name=calc/>
|axialtilt=0°<ref name=saturnsatfact/>
|mass=1.08 * 1020 kg<ref name=saturnsatfact/>
|density=1610 kg/m³<ref name=saturnsatfact/>
|meanradius=252.3 km<ref name=ssdphys>"[http://ssd.jpl.nasa.gov/?sat_phys_par Planetary Satellite Physical Parameters]." Solar System Dynamics, [[JPL]], [[NASA]]. Accessed June 17, 2008.</ref>
|equatorradius=256 km<ref name=saturnsatfact/>
|polarradius=245 km<ref name=saturnsatfact/>
|surfacegrav=0.1133 m/s²<ref name=calc/>
|escapespeed=0.2391 km/s<ref name=calc/>
|surfacearea=799,916 km²<ref name=calc/>
|meantemp=72 K<ref name=Hamilton/>
|maxtemp=145 K<ref name=Spencer>Spencer, J.R., Pearl, J.C., Segura, M., ''et al.'' "[http://www.sciencemag.org/cgi/content/abstract/311/5766/1401 Cassini Encounters Enceladus: Background and the Discovery of a South Polar Hot Spot]." ''Science'' 311(5766):1401-1405, March 10, 2006. {{doi|10.1126/science.1121661}} Accessed June 18, 2008.</ref>
|composition=Water ice, silicates<ref name=Hamilton2>Hamilton,Calvin J. "[http://solarviews.com/eng/enceladusgeyser.htm A Hot Start Might Explain Geysers on Enceladus]." ''Views of the Solar System'', 2007. Accessed June 18, 2008.</ref>
|color=Light blue-white<ref name=Hamilton2/>
|albedo=1.0<ref name=saturnsatfact/><ref name=Hamilton/><ref name=Britannica/>
}}'''Enceladus''' or '''Saturn II''' is the ninth known [[moon]] of [[Saturn]] and the seventh to be discovered. It is also one of three bodies in the [[solar system]] (other than [[Earth]]) known to be [[volcano|volcanically]] active. In fact, recent evidence suggests that Enceladus is the source of Saturn's E ring.

== Discovery and naming ==
[[William Herschel]] discovered Enceladus on August 28, 1789.<ref name=usgs/><ref name=Arrago>Arrago, M. "[http://laplaza.org/~tom/People/Herschel.htm Herschel]." Annual Report of the Board of Regents of the Smithsonian Institution, 1871, pp. 198-223</ref>

Sir [[John Herschel]], his son, suggested the current names of the seven largest satellites of Saturn, including Enceladus. [[Titan (moon)|Titan]] received a generic name, and the other six received names of the Titans of mythology. Enceladus was a giant who fell in battle against Athena in the Titan-Olympian War.<ref name=Lasell>Lassell, William. "[http://articles.adsabs.harvard.edu/full/seri/MNRAS/0008//0000042.000.html Satellites of Saturn]." ''Monthly Notices of the Royal Astronomical Society'', 8(3):42-43, January 14, 1848. Accessed June 4, 2008.</ref>

According to legend, Athena buried Enceladus by heaping dirt on him where he fell. His burial mound is supposed to be the island of Sicily, and more specifically he lies beneath Mount Etna, which vents or erupts as he breathes.<ref name=usgs/><ref name=Arnett>Arnett, Bill. "[http://www.nineplanets.org/enceladus.html Entry for Enceladus]." ''The <s>Nine</s> 8 Planets'', March 30, 2007. Accessed June 17, 2008.</ref> Considering the findings from the exploration of Enceladus by Voyagers 1 and 2 and the [[Cassini-Huygens Mission|Cassini]] orbiter, Enceladus is a more apt name for this moon than Sir John Herschel might have supposed.

== Orbital characteristics ==
Enceladus is in a very slightly eccentric orbit around Saturn, at an average distance of 238,020 km,<ref name=saturnsatfact/><ref name=Britannica>Hubbard, William B. "[http://www.britannica.com/eb/article-9032584 Enceladus]." Encyclopædia Britannica. 2008. Encyclopædia Britannica Online. 18 June 2008.</ref> or within the most dense region of the E ring of Saturn.<ref name=Britannica/>

Enceladus might or might not be in a 1:2 [[orbital resonance]] with [[Dione]].<ref name=Arnett/><ref name=Britannica/><ref name=Porco>Porco, C.C., Helfenstein, P., Thomas, P.C., ''et al.'' "[http://www.sciencemag.org/cgi/content/abstract/311/5766/1393 Cassini Observes the Active South Pole of Enceladus]." ''Science'' 311(5766):1393-1401, March 10, 2006. {{doi|10.1126/science.1123013}} Accessed June 18, 2008.</ref> The sidereal month of Dione is slightly less than twice that of Enceladus.

== Rotational characteristics ==
Enceladus is in [[tidal lock]] with [[Saturn]]. Analysis of 129 images of Enceladus reveals no evidence of any [[libration]], or axial oscillation. However, some astronomers insist that Enceladus must have been in a 1:4 spin/orbit libration in the distant past.<ref name=Porco/>

== Physical characteristics ==
Enceladus has a density of 1.610 kg/m³, 60% greater than that of [[water]]. Hence it is likely composed of water ice and rock. With an albedo of unity or greater, Enceladus is the most reflective body in all the solar system.<ref name=Spencer/>

=== Surface ===
Enceladus has at least five different types of terrain.<ref name=Hamilton/> Regions with impact craters having diameters of 35 km or less, alternate with other regions having no craters. Astronomers suspect extensive remodeling of the surface throughout Enceladus's history.<ref name=Britannica/>

The most surprising finding is the south polar region. It contains multiple fissures, called "tiger stripes" because their appearance suggests the pelt of a [[tiger]]. These fissures radiate significant amounts of heat, with temperatures exceeding 145 K.<ref name=Spencer/> From these fissures, geysers discharge large amounts of water vapor and ice into space. Some of this remains as a tenuous, localized [[atmosphere]] (see below). Other particles escape Enceladus' gravity and thus contribute to the E ring of Saturn.<ref name=Porco/><ref name=Spahn>Spahn, F., Schmidt, J., Albers N., ''et al.'' "[http://www.sciencemag.org/cgi/content/abstract/311/5766/1416 Cassini Dust Measurements at Enceladus and Implications for the Origin of the E Ring]." ''Science'' 311(5766):1416-1418. {{doi|10.1126/science.1121375}} Accessed June 18, 2008.</ref><ref name=Hamilton1>Hamilton, Calvin J. "[http://solarviews.com/eng/enceladuswater.htm Radical! Liquid Water on Enceladus]." ''Views of the Solar System'', March 9, 2006. Accessed June 18, 2008.</ref>

Surprisingly, the E ring is not the only ring to receive contributions from Enceladus. Recent evidence now suggests that some of the ejected particles from Enceladus enter Saturn's magnetic field and eventually reach the A ring.<ref name=Farrell>Farrell, W.M., Kaiser, M.L., Gurnett, D.A., ''et al.'' "[http://www.agu.org/pubs/crossref/2008/2007GL032306.shtml Mass unloading along the inner edge of the Enceladus plasma torus]." ''Geophys. Res. Lett.'' 35(L02203), January 23, 2008. {{doi|10.1029/2007GL032306}} Accessed June 18, 2008.</ref><ref name=Hamilton3>Hamilton, Calvin J. "[http://solarviews.com/eng/giantsponge.htm Saturn's Giant Sponge]." ''Views of the Solar System'', February 5, 2008. Accessed June 18, 2008.</ref>

[[Ammonia]] has ''not'' been detected thus far in the discharge.<ref name=Porco/> This lack would require liquid water to be as hot as 270 K in order to melt in that environment. (The freezing point of water at one standard atmosphere is 273.15 K.)

=== Interior ===
The interior of Enceladus is perhaps differentiated, with a rocky core and an icy mantle. Nimmo and Pappalardo suggest that some relatively low-density material, either in the core or in the mantle, has protruded to the surface near the south pole. This protrusion might even have caused Enceladus to reorient itself to place this material at the south pole.<ref name=Nimmo>Nimmo, F., and Pappalardo, R. T. "[http://www.nature.com/nature/journal/v441/n7093/abs/nature04821.html Diapir-induced reorientation of Saturn's moon Enceladus]." ''Nature'' 441:614-616, June 1, 2006. {{doi|10.1038/nature04821}} Accessed June 18, 2008.</ref>

=== Atmosphere ===
[[Image:Enceladus atmosphere not global.jpg|thumb|200px|left|Stellar occultation reveals that the Enceladan atmosphere is local to the south pole, not global.]]Enceladus has a thin but significant atmosphere, mostly of [[water]] vapor. The chief evidence for this is a deflection of the magnetic field of Saturn as Enceladus moves through it. This atmosphere requires continual replenishment from the cryovolcanic activity.<ref name=Porco/><ref name=atmosphere1>"[http://saturn.jpl.nasa.gov/news/press-release-details.cfm?newsID=553 Cassini Finds an Atmosphere on Saturn's Moon Enceladus]." Press release, [[Jet Propulsion Laboratory|JPL]], March 16, 2005. Accessed June 17, 2008.</ref> In addition, the occultation of the star Bellatrix on July 11, 2005 revealed that the atmosphere is not global in scope, but is probably local to the south polar region, where most of the venting takes place.<ref name=atmosphere2>"[http://photojournal.jpl.nasa.gov/catalog/PIA03552 Enceladus Atmosphere Not Global]." [[Jet Propulsion Laboratory|JPL]], [[National Aeronautics and Space Administration|NASA]], August 30, 2005. Accessed June 17, 2008.</ref>

=== Magnetosphere ===
Enceladus has no detectable magnetic field. However, its atmosphere, such as it is, interferes with Saturn's magnetic field.

=== Models of the south polar geysers ===
[[Image:Enceladus Cold Geyser Model.jpg|thumb|150px|right|The cold geyser model of the production of the geysers]]Astronomers have considered two possible models for the geysers in the south pole. The "cold geyser model" proposes that the hot rocky core applies heat to pockets of liquid water under tremendous pressure.<ref name=Porco/><ref name=Hamilton1/> The major difficulty with this model is that the observed temperatures are not high enough to melt pure water, and no ammonia, which would have lowered the melting point, has been detected. Another possibility is that ice on the surface sublimates (changes directly from solid to gas) from the heat. This, however, is inconsistent with the continuous stream of ejected particles now observed.<ref name=Hamilton4>Hamilton, Calvin J. "[http://solarviews.com/eng/enceladusplumes.htm Scientists Study 'Plumbing' in Plumes of Enceladus]." ''Views of the Solar System'', February 7, 2008. Accessed June 18, 2008.</ref>

== Problems for uniformitarian theories posed by Enceladus ==
Enceladus shows many signs of having internal heat, while its inner companion [[Mimas]] does not. Yet Enceladus is more distant than Mimas from Saturn, and its orbit is less eccentric. That Mimas should have frozen solid, while Enceladus did not freeze and remains tectonically and volcanically active, defies explanation. Spencer ''et al''<ref name=Spencer/> have admitted this problem but suggested that forced libration might explain the heating. Yet if Enceladus changed its axis of rotation, as Nimmo and Pappalardo suggested<ref name=Nimmo/>, then the heat must have arisen ''before'' the libration.

== Observation and Exploration ==
[[Voyager 1]] made the first close rendezvous with Enceladus. [[Project Voyager]] mission controllers discerned from this encounter that Enceladus was in orbit around Saturn at the thickest portion of the E ring. [[Voyager 2]] revealed the surprising variation in the surface of Enceladus, with geologically "old" and "young" regions.<ref name=Britannica/>

The [[Cassini-Huygens mission|Cassini]] orbiter, early in its mission, returned evidence of the volcanic activity of Enceladus and its possible role as the source of the particlate matter in the E ring.<ref name=Britannica/> Mission planners then scheduled many more rendezvous with Enceladus. With each encounter, Cassini returned ever more remarkable findings about Enceladus.

The Cassini-Huygens mission is now (June 17, 2008) about to begin its two-year extended mission. This mission will include even more rendezvous with this remarkable object.

== Gallery ==
<gallery>
Image:Enceladus Voyager.jpg|Enceladus, taken by Voyager 2
Image:Enceladus false color stripes.jpg|Enceladus in false color, with enhancement of the south polar fissures
Image:Enceladus tiger stripes.jpg|A close-up photograph of the "tiger stripe" fissures
Image:Enceladus heat map.jpg|Heat emanating from the fissures
Image:Enceladus fountains monochrome.jpg|Geysers of Enceladus, in monochrome
Image:Enceladus fountains.jpg|Geysers of Enceladus, in enhanced color
Image:Enceladus jets bright.jpg|Distant photograph of the south polar geysers
Image:Enceladus jet blue.jpg|Enhanced color photograph of south polar geysers
Image:Enceladus interior.jpg|Cutaway of Enceladus showing possible protruding material from the mantle and/or the core
</gallery>

== References ==
{{reflist|2}}
{{Solarsystem}}

Triton

2015-01-28T00:23:46Z

ScKinney: /* Physical characteristics */

{{Planet
|image=Triton1_Voyager2.jpg
|caption=True-color image of Triton's south pole, by [[Voyager 2]]
|date=October 10, 1846<ref name=usgs>"[http://planetarynames.wr.usgs.gov/append7.html Gazetteer of Planetary Nomenclature: Planetary Body Names and Discoverers]." US Geological Survey, Jennifer Blue, ed. March 31, 2008. Accessed May 9, 2008.</ref>
|discname=William Lassell<ref name=usgs/><ref name=Hamilton>Hamilton, Calvin J. "[http://www.solarviews.com/eng/triton.htm Entry for Triton]." ''Views of the Solar System'', 1997. Accessed May 9, 2008.</ref>
|origname=Demigod and son of Poseidon and Amphitrite.<ref name=usgs/>
|primary=Neptune
|order=7
|periapsis=354,754 km<ref name=calc>Calculated</ref>
|apoapsis=354,766 km<ref name=calc/>
|semimajor=354,760 km<ref name=neptunesatfact>[http://nssdc.gsfc.nasa.gov/planetary/factsheet/neptuniansatfact.html Neptunian Satellite Fact Sheet], [[National Aeronautics and Space Administration|NASA]], January 22, 2008. Accessed May 9, 2008.</ref>
|eccentricity=0.000016<ref name=neptunesatfact/>
|sidereal=-5.876854 da<ref name=neptunesatfact/>
|inclination=157.345°<ref name=neptunesatfact/>
|siderealday=-5.876854 da<ref name=neptunesatfact/>
|axialtilt=0°
|mass=2.14 * 1022 kg<ref name=neptunesatfact/>
|meanradius=1,353.4 km<ref name=neptunesatfact/>
|density=2,050 kg/m³<ref name=neptunesatfact/>
|surfacegrav=0.77955 m/s²<ref name=calc/>
|escapespeed=1.4526 km/s<ref name=calc/>
|surfacearea=23,017,715 km²<ref name=calc/>
|meantemp=34.5 K<ref name=Arnett>Arnett, Bill. "[http://www.nineplanets.org/triton.html Entry for Triton]." ''The <s>Nine</s> 8 Planets'', October 13, 1998. Accessed May 9, 2008.</ref>
|composition=25% [[water]] ice, 75% rock<ref name=Arnett/>
|color=Pinkish-white
|albedo=0.76<ref name=neptunesatfact/>
}}'''Triton''', or '''Neptune I''', is the seventh [[moon]] of [[Neptune]] in order of distance, the first moon of Neptune to be discovered, and the seventh largest moon in all the [[solar system]]. It is also the only moon that, while large enough to be called a [[dwarf planet]] were it not a satellite, revolves around its primary with a motion retrograde to the primary's own rotation about its axis. This remarkable object thus poses an interesting problem for [[uniformitarianism|uniformitarian]] [[astronomy|astronomical]] theories.

== Discovery ==
The [[United Kingdom|British]] astronomer [[William Laskell]] discovered Triton on October 10, 1846, less than one month following the discovery of Neptune itself.<ref name=Hamilton/><ref name=Arnett/> Laskell observed what he at first took to be a ring, but which later proved to be an artifact of the distortion that his new telescope produced. However, Laskell also observed a large satellite, and that image was ''not'' due to distortion.<ref name=apod>"[http://antwrp.gsfc.nasa.gov/apod/ap971123.html Triton: Neptune's Largest Moon]." ''Astronomy Picture of the Day'', [[National Aeronautics and Space Administration|NASA]], November 23, 1997. Accessed May 9, 2007.</ref>

Triton is named after a demigod of the sea, son of Poseidon and his lover Amphitrite. The [[France|French]] astronomer Camille Flammarion is credited with suggesting this name.<ref name=usgs/> For more than a century, Triton was the only satellite of Neptune known to man.

== Orbital characteristics ==
The most remarkable characteristic of this object is its retrograde motion.<ref name=Hamilton/><ref name=Arnett/> Triton takes 5.876854 Julian days to complete one orbit about Neptune—in a direction opposite to Neptune's own rotation.<ref name=neptunesatfact/> This makes Triton unique among moons large enough for their self-gravity to force them into hydrostatic-equilibrium (that is, spheroidal) shape. Yet Triton's orbit is nearly circular; its eccentricity is the least of those of the thirteen satellites of Neptune and one of the lowest of the orbital eccentricities of all solar system objects.<ref name=neptunesatfact/>

== Rotational characteristics ==
Triton is [[tidal locking|tidally locked]] and thus always keeps the same face toward Neptune. Thus its sidereal month and day are the same length, and furthermore its sidereal day is also retrograde.

== Physical characteristics ==
Triton's mass is 2.14 * 1022 kg, more than 29% that of [[Earth]]'s [[Moon]] and the seventh-largest mass of all the moons in the solar system. With a density of 2,050 kg/m³, it has far more rock and far less water ice than the core of Neptune.<ref name=Arnett/>

Triton is also the coldest object on record in the solar system, with a mean temperature of only 34.5 kelvins. This is probably due to Triton's unusually high geometric albedo, which causes it to reflect away energy from the Sun that it might otherwise absorb as heat.<ref name=Arnett/> Yet in the decade since Voyager 2's flyby of Triton in 1989, Triton's trace atmosphere thickened, and its mean temperature rose by two to three kelvins, a radical proportional warming. This was probably due to Triton's unusual orbital inclination, and the exposure of its south pole to more solar radiation than usual.<ref name=mit>"[http://web.mit.edu/newsoffice/1998/triton.html MIT researcher finds evidence of global warming on Neptune's largest moon]," [[Massachusetts Institute of Technology]], June 24, 1998. Accessed May 9, 2008.</ref>

Triton's surface is considered relatively young, not more than 10 million years by uniformitarian models.<ref name=Schenk>Schenk, Paul M., and Zahnle, Kevin. "[http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WGF-4PFW6FV-2&_user=10&_coverDate=12%2F01%2F2007&_rdoc=10&_fmt=summary&_orig=browse&_srch=doc-info(%23toc%236821%232007%23998079998%23674080%23FLA%23display%23Volume)&_cdi=6821&_sort=d&_docanchor=&_ct=19&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=cea35d4a7d94052a325123729f8dfcf0 On the Negligible Surface Age of Triton]." ''Icarus'', 192(1):135-149, December 1, 2007. <doi:10.1016/j.icarus.2007.07.004 > Accessed May 9, 2008.</ref> Geologists count 100 impact craters on the leading hemisphere (the one facing in the direction of its motion around Neptune) and suspect that debris from collisions involving the inner or outer moons of Neptune have struck Triton on this leading surface.

Triton has many deep chasms on its surface. In addition, [[Voyager 2]] recorded multiple [[geyser]]-like eruptions of [[nitrogen]] gas and dust from beneath the surface. This gas has created a very low-pressure "[[atmosphere]]". It is the only moon with an atmosphere besides [[Titan (moon)]].

The trailing hemisphere of Triton has a puckered surface with few, widely-spaced ridges and valleys and far fewer impact craters. This "cantaloupe terrain" has not been observed on any other celestial body.<ref name=ps>"[http://www.planetary.org/explore/topics/neptune/triton.html Neptune's Moon Triton]." ''The Planetary Society''. Accessed May 10, 2008.</ref>

== Theories of origin ==
Triton's retrograde orbit continues to puzzle secular astronomers. Virtually none of them believe that Triton formed at the same time as did Neptune; the [[nebula hypothesis]] simply would not allow that. The general consensus, therefore, is that Triton is a captured [[Trans-Neptunian Objects|trans-Neptunian object]] and possibly a [[Kuiper Belt]] object.<ref name=Hamilton/><ref name=Arnett/><ref name=Goudarzi>Goudarzi, Sara. "[http://www.space.com/scienceastronomy/060510_triton_origin.html Neptune Might Have Captured Triton]." ''<http://www.space.com/>'', May 10, 2006. Accessed May 10, 2008.</ref> Some authorities suggest that the capture and its aftermath might have melted Triton's interior and caused it to differentiate.<ref name=Hamilton/><ref name=Arnett/><ref name=darling>"[http://www.daviddarling.info/encyclopedia/T/Triton.html Entry for Triton]." ''The Internet Encyclopedia of Science''. Accessed May 10, 2008.</ref>

But ''how'' that capture might have occurred remains an open question. The two favorite theories are:
# Triton collided with another object, the remains of which persist today as part of Neptune's ring system.<ref name=Arnett/> The primary difficulty with that theory, as opposed to any other capture theory, is the question of what exactly became of the remains of any object large enough to slow Triton down to enable Neptune to capture it. Neptune's ring system would not appear to have nearly enough matter to account for the destruction of such an object.
# Triton was originally part of a binary or near-binary system, similar to the system of [[Pluto]] and [[Charon]], and Neptune separated Triton from its former companion as it passed.<ref name=Goudarzi/><ref name=Clark>Clark, Stuart. "[http://space.newscientist.com/article/mg19025514.200-how-neptune-snagged-a-passing-moon.html How Neptune snagged a passing moon]." ''New Scientist'', 2551:8, May 10, 2006. Accessed May 10, 2008.</ref><ref name=Stephens>Stephens, Tim. "[http://currents.ucsc.edu/05-06/05-15/triton.asp New capture scenario explains origin of Neptune's oddball moon Triton]." ''UC Santa Cruz Currents'', May 15, 2006. Accessed May 10, 2008.</ref><ref name=Agnor>Agnor, Craig B., and Hamilton, Douglas. "[http://www.nature.com/nature/journal/v441/n7090/abs/nature04792.html;jsessionid=96C8003B3E24E3AEA9816D7B1225884F Neptune's capture of its moon Triton in a binary–planet gravitational encounter]." ''Nature'', 441:192-194, May 11, 2006. <doi:10.1038/nature04792> Accessed: May 10, 2008.</ref> However, Agnor and Hamilton, the proponents of this three-body capture model, make no attempt to identify Triton's former companion, if it had one. As a further complication, Triton itself is larger than any other Kuiper belt object except the [[dwarf planet]] [[Pluto]]. Pluto's orbit is, of course, so eccentric that its periapsis is less than Neptune's apoapsis, so that occasionally Pluto's orbit carries it closer to the Sun than is Neptune. But as one commentator observed,{{cquote|The unusual nature of Triton's orbit, the similarity of bulk properties between Pluto and Triton, and the highly eccentric, Neptune-crossing nature of Pluto's orbit suggest some historical connection between them. Exactly what this might be is purely conjecture at this time however.<ref name=Arnett/>}}

A further problem for ''any'' capture theory is that Triton's orbit, though retrograde, is almost perfectly circular. Immediately following capture, Triton's orbit would necessarily have been highly eccentric. Ćuk and Gladman admit that tidal deceleration alone would have taken longer than the supposed age of the solar system (i.e. longer than 4.5 billion years) for the orbit to become so circular. Therefore some other mechanisms must have acted to produce the observed outcome. Ćuk and Gladman propose repeated collisions with other satellites and the absorption of the resulting debris by Triton.<ref name=Gladman>Ćuk, Matija, and Gladman, Brett. J. "[http://adsabs.harvard.edu/abs/2005ApJ...626L.113C Constraints on the Orbital Evolution of Triton]." ''Astrophys. J.'' 626(2):L113-L116, June 2005. Accessed May 10, 2008.</ref>

Triton's retrograde orbit does suggest a theoretical "doom" for Triton. With every orbit, tidal forces slow Triton by a tiny amount. At the present rate, secular astronomers estimate that in 1.4 or 3.6 billion years, Triton will pass within Neptune's [[Roche limit]] and disintegrate.<ref name=Chyba>Chyba, C. F.; Jankowski, D. G.; Nicholson, P. D. "[http://adsabs.harvard.edu/abs/1989A&A...219L..23C Tidal evolution in the Neptune-Triton system]." ''Astronomy and Astrophysics'', 219(1-2):L23-L26, July 1989. Accessed May 10, 2008.</ref>

== Gallery ==
<gallery>
Image:Triton.gif|Triton
Image:Triton2_Voyager2.jpg|Triton by Voyager 2
</gallery>
==References==
{{reflist|2}}

== See also ==
John Gribbin, ''Companion to the Cosmos'' (Little, Brown & Company, 1996)

{{Solarsystem}}

Triton

2015-01-28T00:22:20Z

ScKinney: /* Physical characteristics */

{{Planet
|image=Triton1_Voyager2.jpg
|caption=True-color image of Triton's south pole, by [[Voyager 2]]
|date=October 10, 1846<ref name=usgs>"[http://planetarynames.wr.usgs.gov/append7.html Gazetteer of Planetary Nomenclature: Planetary Body Names and Discoverers]." US Geological Survey, Jennifer Blue, ed. March 31, 2008. Accessed May 9, 2008.</ref>
|discname=William Lassell<ref name=usgs/><ref name=Hamilton>Hamilton, Calvin J. "[http://www.solarviews.com/eng/triton.htm Entry for Triton]." ''Views of the Solar System'', 1997. Accessed May 9, 2008.</ref>
|origname=Demigod and son of Poseidon and Amphitrite.<ref name=usgs/>
|primary=Neptune
|order=7
|periapsis=354,754 km<ref name=calc>Calculated</ref>
|apoapsis=354,766 km<ref name=calc/>
|semimajor=354,760 km<ref name=neptunesatfact>[http://nssdc.gsfc.nasa.gov/planetary/factsheet/neptuniansatfact.html Neptunian Satellite Fact Sheet], [[National Aeronautics and Space Administration|NASA]], January 22, 2008. Accessed May 9, 2008.</ref>
|eccentricity=0.000016<ref name=neptunesatfact/>
|sidereal=-5.876854 da<ref name=neptunesatfact/>
|inclination=157.345°<ref name=neptunesatfact/>
|siderealday=-5.876854 da<ref name=neptunesatfact/>
|axialtilt=0°
|mass=2.14 * 1022 kg<ref name=neptunesatfact/>
|meanradius=1,353.4 km<ref name=neptunesatfact/>
|density=2,050 kg/m³<ref name=neptunesatfact/>
|surfacegrav=0.77955 m/s²<ref name=calc/>
|escapespeed=1.4526 km/s<ref name=calc/>
|surfacearea=23,017,715 km²<ref name=calc/>
|meantemp=34.5 K<ref name=Arnett>Arnett, Bill. "[http://www.nineplanets.org/triton.html Entry for Triton]." ''The <s>Nine</s> 8 Planets'', October 13, 1998. Accessed May 9, 2008.</ref>
|composition=25% [[water]] ice, 75% rock<ref name=Arnett/>
|color=Pinkish-white
|albedo=0.76<ref name=neptunesatfact/>
}}'''Triton''', or '''Neptune I''', is the seventh [[moon]] of [[Neptune]] in order of distance, the first moon of Neptune to be discovered, and the seventh largest moon in all the [[solar system]]. It is also the only moon that, while large enough to be called a [[dwarf planet]] were it not a satellite, revolves around its primary with a motion retrograde to the primary's own rotation about its axis. This remarkable object thus poses an interesting problem for [[uniformitarianism|uniformitarian]] [[astronomy|astronomical]] theories.

== Discovery ==
The [[United Kingdom|British]] astronomer [[William Laskell]] discovered Triton on October 10, 1846, less than one month following the discovery of Neptune itself.<ref name=Hamilton/><ref name=Arnett/> Laskell observed what he at first took to be a ring, but which later proved to be an artifact of the distortion that his new telescope produced. However, Laskell also observed a large satellite, and that image was ''not'' due to distortion.<ref name=apod>"[http://antwrp.gsfc.nasa.gov/apod/ap971123.html Triton: Neptune's Largest Moon]." ''Astronomy Picture of the Day'', [[National Aeronautics and Space Administration|NASA]], November 23, 1997. Accessed May 9, 2007.</ref>

Triton is named after a demigod of the sea, son of Poseidon and his lover Amphitrite. The [[France|French]] astronomer Camille Flammarion is credited with suggesting this name.<ref name=usgs/> For more than a century, Triton was the only satellite of Neptune known to man.

== Orbital characteristics ==
The most remarkable characteristic of this object is its retrograde motion.<ref name=Hamilton/><ref name=Arnett/> Triton takes 5.876854 Julian days to complete one orbit about Neptune—in a direction opposite to Neptune's own rotation.<ref name=neptunesatfact/> This makes Triton unique among moons large enough for their self-gravity to force them into hydrostatic-equilibrium (that is, spheroidal) shape. Yet Triton's orbit is nearly circular; its eccentricity is the least of those of the thirteen satellites of Neptune and one of the lowest of the orbital eccentricities of all solar system objects.<ref name=neptunesatfact/>

== Rotational characteristics ==
Triton is [[tidal locking|tidally locked]] and thus always keeps the same face toward Neptune. Thus its sidereal month and day are the same length, and furthermore its sidereal day is also retrograde.

== Physical characteristics ==
Triton's mass is 2.14 * 1022 kg, more than 29% that of [[Earth]]'s [[Moon]] and the seventh-largest mass of all the moons in the solar system. With a density of 2,050 kg/m³, it has far more rock and far less water ice than the core of Neptune.<ref name=Arnett/>

Triton is also the coldest object on record in the solar system, with a mean temperature of only 34.5 kelvins. This is probably due to Triton's unusually high geometric albedo, which causes it to reflect away energy from the Sun that it might otherwise absorb as heat.<ref name=Arnett/> Yet in the decade since Voyager 2's flyby of Triton in 1989, Triton's trace atmosphere thickened, and its mean temperature rose by two to three kelvins, a radical proportional warming. This was probably due to Triton's unusual orbital inclination, and the exposure of its south pole to more solar radiation than usual.<ref name=mit>"[http://web.mit.edu/newsoffice/1998/triton.html MIT researcher finds evidence of global warming on Neptune's largest moon]," [[Massachusetts Institute of Technology]], June 24, 1998. Accessed May 9, 2008.</ref>

Triton's surface is considered relatively young, not more than 10 million years by uniformitarian models.<ref name=Schenk>Schenk, Paul M., and Zahnle, Kevin. "[http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WGF-4PFW6FV-2&_user=10&_coverDate=12%2F01%2F2007&_rdoc=10&_fmt=summary&_orig=browse&_srch=doc-info(%23toc%236821%232007%23998079998%23674080%23FLA%23display%23Volume)&_cdi=6821&_sort=d&_docanchor=&_ct=19&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=cea35d4a7d94052a325123729f8dfcf0 On the Negligible Surface Age of Triton]." ''Icarus'', 192(1):135-149, December 1, 2007. <doi:10.1016/j.icarus.2007.07.004 > Accessed May 9, 2008.</ref> Geologists count 100 impact craters on the leading hemisphere (the one facing in the direction of its motion around Neptune) and suspect that debris from collisions involving the inner or outer moons of Neptune have struck Triton on this leading surface.

Triton has many deep chasms on its surface. In addition, [[Voyager 2]] recorded multiple [[geyser]]-like eruptions of [[nitrogen]] gas and dust from beneath the surface. This gas has created a very low-pressure "[[atmosphere]]". It is the only moon with an atmosphere besides [[Titan]].

The trailing hemisphere of Triton has a puckered surface with few, widely-spaced ridges and valleys and far fewer impact craters. This "cantaloupe terrain" has not been observed on any other celestial body.<ref name=ps>"[http://www.planetary.org/explore/topics/neptune/triton.html Neptune's Moon Triton]." ''The Planetary Society''. Accessed May 10, 2008.</ref>

== Theories of origin ==
Triton's retrograde orbit continues to puzzle secular astronomers. Virtually none of them believe that Triton formed at the same time as did Neptune; the [[nebula hypothesis]] simply would not allow that. The general consensus, therefore, is that Triton is a captured [[Trans-Neptunian Objects|trans-Neptunian object]] and possibly a [[Kuiper Belt]] object.<ref name=Hamilton/><ref name=Arnett/><ref name=Goudarzi>Goudarzi, Sara. "[http://www.space.com/scienceastronomy/060510_triton_origin.html Neptune Might Have Captured Triton]." ''<http://www.space.com/>'', May 10, 2006. Accessed May 10, 2008.</ref> Some authorities suggest that the capture and its aftermath might have melted Triton's interior and caused it to differentiate.<ref name=Hamilton/><ref name=Arnett/><ref name=darling>"[http://www.daviddarling.info/encyclopedia/T/Triton.html Entry for Triton]." ''The Internet Encyclopedia of Science''. Accessed May 10, 2008.</ref>

But ''how'' that capture might have occurred remains an open question. The two favorite theories are:
# Triton collided with another object, the remains of which persist today as part of Neptune's ring system.<ref name=Arnett/> The primary difficulty with that theory, as opposed to any other capture theory, is the question of what exactly became of the remains of any object large enough to slow Triton down to enable Neptune to capture it. Neptune's ring system would not appear to have nearly enough matter to account for the destruction of such an object.
# Triton was originally part of a binary or near-binary system, similar to the system of [[Pluto]] and [[Charon]], and Neptune separated Triton from its former companion as it passed.<ref name=Goudarzi/><ref name=Clark>Clark, Stuart. "[http://space.newscientist.com/article/mg19025514.200-how-neptune-snagged-a-passing-moon.html How Neptune snagged a passing moon]." ''New Scientist'', 2551:8, May 10, 2006. Accessed May 10, 2008.</ref><ref name=Stephens>Stephens, Tim. "[http://currents.ucsc.edu/05-06/05-15/triton.asp New capture scenario explains origin of Neptune's oddball moon Triton]." ''UC Santa Cruz Currents'', May 15, 2006. Accessed May 10, 2008.</ref><ref name=Agnor>Agnor, Craig B., and Hamilton, Douglas. "[http://www.nature.com/nature/journal/v441/n7090/abs/nature04792.html;jsessionid=96C8003B3E24E3AEA9816D7B1225884F Neptune's capture of its moon Triton in a binary–planet gravitational encounter]." ''Nature'', 441:192-194, May 11, 2006. <doi:10.1038/nature04792> Accessed: May 10, 2008.</ref> However, Agnor and Hamilton, the proponents of this three-body capture model, make no attempt to identify Triton's former companion, if it had one. As a further complication, Triton itself is larger than any other Kuiper belt object except the [[dwarf planet]] [[Pluto]]. Pluto's orbit is, of course, so eccentric that its periapsis is less than Neptune's apoapsis, so that occasionally Pluto's orbit carries it closer to the Sun than is Neptune. But as one commentator observed,{{cquote|The unusual nature of Triton's orbit, the similarity of bulk properties between Pluto and Triton, and the highly eccentric, Neptune-crossing nature of Pluto's orbit suggest some historical connection between them. Exactly what this might be is purely conjecture at this time however.<ref name=Arnett/>}}

A further problem for ''any'' capture theory is that Triton's orbit, though retrograde, is almost perfectly circular. Immediately following capture, Triton's orbit would necessarily have been highly eccentric. Ćuk and Gladman admit that tidal deceleration alone would have taken longer than the supposed age of the solar system (i.e. longer than 4.5 billion years) for the orbit to become so circular. Therefore some other mechanisms must have acted to produce the observed outcome. Ćuk and Gladman propose repeated collisions with other satellites and the absorption of the resulting debris by Triton.<ref name=Gladman>Ćuk, Matija, and Gladman, Brett. J. "[http://adsabs.harvard.edu/abs/2005ApJ...626L.113C Constraints on the Orbital Evolution of Triton]." ''Astrophys. J.'' 626(2):L113-L116, June 2005. Accessed May 10, 2008.</ref>

Triton's retrograde orbit does suggest a theoretical "doom" for Triton. With every orbit, tidal forces slow Triton by a tiny amount. At the present rate, secular astronomers estimate that in 1.4 or 3.6 billion years, Triton will pass within Neptune's [[Roche limit]] and disintegrate.<ref name=Chyba>Chyba, C. F.; Jankowski, D. G.; Nicholson, P. D. "[http://adsabs.harvard.edu/abs/1989A&A...219L..23C Tidal evolution in the Neptune-Triton system]." ''Astronomy and Astrophysics'', 219(1-2):L23-L26, July 1989. Accessed May 10, 2008.</ref>

== Gallery ==
<gallery>
Image:Triton.gif|Triton
Image:Triton2_Voyager2.jpg|Triton by Voyager 2
</gallery>
==References==
{{reflist|2}}

== See also ==
John Gribbin, ''Companion to the Cosmos'' (Little, Brown & Company, 1996)

{{Solarsystem}}

Jupiter

2015-01-28T00:18:55Z

ScKinney: /* Problems for uniformitarian theories */

{{Planet
| image=Jumpsas.jpg
| caption=This processed color image of Jupiter was produced in 1990 by the U.S. Geological Survey from a Voyager image captured in 1979
|symbol=Jupiter symbol.svg
|discname=Known to ancients
|origname=Roman king of gods<ref name=nasa1>"[http://solarsystem.jpl.nasa.gov/planets/profile.cfm?Object=Jupiter&Display=Overview Entry for Jupiter]." ''Solar System Exploration'', [[NASA]]. Accessed March 3, 2008.</ref>
|order=6
|primary=Sun
|periapsis=4.95 AU<ref name=nasa1/>
|apoapsis=5.46 AU<ref name=nasa1/>
|semimajor=5.203 AU<ref name=nasa1/><ref name=nasa2>Williams, David R. "[http://nssdc.gsfc.nasa.gov/planetary/factsheet/jupiterfact.html Jupiter Fact Sheet]." National Space Science Data Center, [[NASA]], November 2, 2007. Accessed March 2, 2008.</ref>
|bode=5.2 AU<ref name=calc>Calculated</ref>
|circumference=32.675 AU<ref name=nasa1/>
|eccentricity=0.048<ref name=nasa1/>
|sidereal=11.862 a<ref name=nasa1/><ref name=nasa2/>
|synodic=398.88 da (1.092 a)<ref name=nasa2/>
|orbitspeed=13.07 km/s<ref name=nasa1/><ref name=nasa2/>
|inclination=1.305°<ref name=nasa1/>
|reference=the ecliptic
|siderealday=9.925 h (0.414 da)<ref name=nasa1/><ref name=nasa2/>
|solarday=9.9259 h<ref name=nasa2/>
|axialtilt=3.13°<ref name=nasa1/>
|mass=1.8986 * 1027 kg (317.705 * earth)<ref name=nasa1/>
|density=1,326 kg/m³<ref name=nasa1/>
|surfacegrav=22.88 m/s² (2.333 ''g'')<ref name=nasa1/>
|escapespeed=59.56 km/s<ref name=nasa1/>
|equatorradius =71,492 km<ref name=nasa1/>
|surfacearea=61,400,000,000 km² (120.375 * earth)<ref name=nasa1/>
|meantemp=152 K<ref name=nasa1/>
|moons=66
|composition=90% hydrogen and 10% helium<ref name=nasa1/>
|color=Colored latitudinal bands
|albedo=0.52<ref name=ssdphys>"[http://ssd.jpl.nasa.gov/?planet_phys_par Planet Physical Characteristics]." Solar System Dynamics, [[JPL]], [[NASA]]. Accessed March 3, 2008.</ref>
|mfd=4.28 G <ref name=jupiterfact>"[http://nssdc.gsfc.nasa.gov/planetary/factsheet/jupiterfact.html Jupiter Fact Sheet]," [[National Aeronautics and Space Administration|NASA]], November 2, 2007. Accessed May 12, 2008.</ref>
|pmdm=1.55 * 1027 N-m/T<ref name=Humphreys>Humphreys, D. R. "[http://www.creationresearch.org/crsq/articles/21/21_3/21_3.html The Creation of Planetary Magnetic Fields]." ''[[Creation Research Society Quarterly]]'' 21(3), December 1984. Accessed April 29, 2008.</ref>
|cmdm=1.79 * 1027 N-m/T<ref name=Humphreys/>
|mdt=45,469 a<ref name=calc/>
|mhl=31,516 a<ref name=calc/>
}}
'''Jupiter''' is the fifth [[planet]] from the [[sun]], and the most massive. In fact, this [[gas giant]] is the largest body in the [[solar system]] except for the sun itself, and more than two times as massive as all the other planets combined. In composition it closely resembles a [[star]], so much so that some authorities hold that had it been eighty times as massive, it would have become a star.

== Ancient knowledge and naming ==
Named after the ruler of the Roman gods, Jupiter is large and bright enough to be seen by the naked eye. In fact it is the fourth-brightest object in the night sky, after the [[Sun]], the [[Moon]], and the planet [[Venus]].<ref name=arnett>Arnett, Bill. "[http://www.nineplanets.org/jupiter.html Entry for Jupiter]." ''The <s>Nine</s> 8 Planets'', April 10, 2005. Accessed March 3, 2008.</ref> Jupiter is conspicuous and easy to recognize. An observer carrying 7-power field glasses (of a type used for birding or hunting) will see a round disk that shines steadily. An observer with a small telescope should also be able to resolve the [[Galilean moons]], as [[Galileo Galilei]] himself did. They will appear, as they did to Galileo, as "stars" traveling in "formation" with Jupiter and changing their positions relative to Jupiter in a single night of observation.

The [[Babylonia]]ns believed that their god [[Marduk]] set Jupiter in the sky to guide the stars.<ref name=nelson>Nelson, Clark. "[http://www.timeemits.com/HoH_Articles/399-Day_Mean_Synodic_Period_of_Jupiter.htm 399-day Mean Synodic Period of Jupiter]." <http://www.timeemits.com/>, 2006. Accessed March 3, 2008.</ref> Jupiter might have had an influence in the invention of several ancient calendars, including the Mayan calendar, the Egyptian calendar, the ancient (pre-Hillel II) Hebrew calendar, and possibly the calendar in use (at least by the [[Seth]]ite generations of [[Adam]]) before the [[Great flood|Great Flood]]).<ref name=nelson/>

The name of the Roman god derives from the Latin "dyeu-pater" and "ius-pater."<ref>http://www.etymonline.com/index.php?term=Jupiter</ref>

== Orbital characteristics ==
Jupiter completes one slightly eccentric orbit around the [[Sun]] in 11.86 years, and returns to the same position in [[Earth]]'s night sky in roughly 399 years.<ref name=nasa2/><ref name=nelson/> Its mean distance from the Sun is about 5.2 AU--almost exactly the distance predicted by the [[Titius-Bode law]] of planetary distances. Though Jupiter is the fifth ''planet'' from the Sun, it is actually the ''sixth'' object of a size requiring the assumption of a spheroidal shape. Hence ''n=6'' is the proper number to use in the Bode's Law formula.

== Rotational characteristics ==
Jupiter has a very short sidereal day of about 9.92 hours. However, its latitudinal cloud bands rotate at different speeds, and some of these appear to rotate retrograde. Astronomers once calculated the Jovian day from observations of the equatorial cloud band, but today they rely on the periodicity of Jupiter's magnetic field.<ref name=nasa3>Gierasch, Peter J., and Philip D. Nicholson. "Jupiter." World Book Online Reference Center. 2004. World Book, Inc. <http://www.worldbookonline.com/wb/Article?id=ar293080.> Hosted as "[http://www.nasa.gov/worldbook/jupiter_worldbook.html Entry for Jupiter]," World Book at [[NASA]]. Accessed March 3, 2008.</ref>

== Physical characteristics ==
Jupiter is about 318 times as massive as Earth, and has a radius of 71,492 km (44,423 miles). Its atmosphere is composed primarily of 86% [[hydrogen]], 14% [[helium]], and traces of [[methane]], [[ammonia]], [[phosphine]], [[water]], [[acetylene]], [[ethane]], [[germanium]], and [[carbon monoxide]].<ref name=nasa3/> It is so thick that no record exists of the surface, if Jupiter has one in the traditional sense--though Jupiter might have a heavy-metal core having a composition similar to that of [[Earth]] but 20 to 30 times as massive.<ref name=nasa3/>

=== The Great Red Spot and other storms ===
The planet endures continual storms. The most famous of these is the Great Red Spot, which has raged for at least three hundred years. The most precise estimate of its duration is 342 years,<ref name=Than>Than, Ker. "[http://www.space.com/scienceastronomy/060731_red_spots.html Differences Spotted in Jupiter's Big Red Storms]." <http://www.space.com/>, July 31, 2006. Accessed March 3, 2008.</ref> but this might refer merely to the first time that someone observed it with a telescope capable of resolving it. It is large enough to encompass the entirety of the [[Earth]] and rotates anticlockwise along Jupiter's equator. Winds at its edge circulate at 360 km/h<ref name=nasa3/>, far faster than those of the most powerful [[hurricane]] ever recorded on Earth.

=== Radiation of heat ===
Jupiter actually radiates 1.7 times the heat that strikes it from the Sun.<ref name=Weisstein>Weisstein, Eric W. "[http://scienceworld.wolfram.com/astronomy/Jupiter.html Jupiter]." ''Eric Weisstein's World of Astronomy'', accessed March 3, 2008.</ref> This could be due to Kelvin-Helmholtz gravitational compression, a process that also limits the size that Jupiter can have.<ref name=arnett/> In this process, the planet's cooling causes it to compress, which in turn heats up Jupiter's core.

== Magnetosphere ==
Jupiter has a magnetic field about 14 times as strong as that of Earth. Specifically, its [[magnetic dipole moment]] amounts to 1.55 * 1027 N-m/T, higher than that of any object except the [[Sun]]. It is so high, in fact, that by [[Russell Humphreys]]' model for planetary magnetic fields, Jupiter's field must have formed with ''all'' of its mass aligned for the maximum cumulative magnetic dipole moment, instead of the usual 25%. By this assumption, the magnetic dipole moment of Jupiter at creation must have been 1.79 * 1027 N-m/T. The half-life of this field is longer than 31,500 Julian years.

This field tends to shield Jupiter from the [[solar wind]]. However, the field has also trapped large numbers of radioactive particles in a Van-Allen-like radiation belt<ref name=nasa3/> that actually encompasses the orbits of the seven innermost moons. The magnetic field extends beyond the far side of Jupiter for at least 700 million kilometers.<ref name=nasa3/>

The very strong magnetic field of Jupiter is extraordinary by any standard. The Humphreys model has passed two key tests of its predictive value, one at [[Uranus]] and the other at [[Neptune]].<ref name=Humphreys2>Humphreys, D. R. "[http://www.icr.org/index.php?module=articles&action=view&page=329 Beyond Neptune: Voyager II Supports Creation]." [[Institute for Creation Research]]. Accessed April 30, 2008</ref> That model normally assumes that God formed any given celestial body initially out of water, with its molecules partially aligned for maximum cumulative effect, and then transmuted the molecules after the magnetic field was established. For most celestial bodies thus far observed, an alignment fraction of 25% suffices to establish a magnetic dipole moment at creation. But Jupiter's magnetic dipole moment is far too high to have resulted from an initial alignment of 25%. An alignment of 100% seems to be required, the highest fraction allowable and the highest fraction of all celestial bodies observed to date. This implies that God made Jupiter to be a beacon in the night sky, in more ways than merely by making it large.

Jupiter's orbit is inclined 1.305 degrees to the ecliptic, so Jupiter appears, in turn, in each constellation of the Zodiac. In fact, its 399-day synodic year places it in a different constellation of the Zodiac at the same point in each succeeding year. Pratt<ref name=Pratt>Pratt, John C. "[http://www.johnpratt.com/items/docs/lds/meridian/2005/zodiac.html The Constellations Tell of Christ]." ''Meridian'', June 15, 2005. Accessed May 12, 2008.</ref> shows that the members of the Zodiac, and a number of closely associated constellations, presage the life and ministry of [[Jesus Christ]]. If Jupiter is indeed a beacon, then it could not have been better placed.

== Ring system ==
Jupiter does have a ring, consisting of three components, called the halo, the main ring, and the gossamer ring. This ring lies entirely within the region occupied by the four innermost moons, and probably derives its substance from escaping dust from the two innermost moons, [[Metis]] and [[Adrastea]]. The average size of the ring particles is 10 microns, comparable in size to the particles in [[tobacco]] smoke.<ref name=nasa4>Harvey, Samantha. "[http://solarsystem.jpl.nasa.gov/planets/profile.cfm?Object=Jupiter&Display=Rings Jupiter:Rings]." ''Solar System Exploration'', [[NASA]], February 7, 2008. Accessed March 3, 2008.</ref>

==Shoemaker-Levy==
In 1994, scientists were able to witness fragments of the comet Shoemaker-Levy 9 collide with Jupiter. These collisions laster for 6 days, starting on July 16th of that year, and was the first cosmic collision to be observed. During the impacts, at least 21 separate fragments with a size of up to 2 kilometers hit Jupiter, leaving scars in its atmosphere larger than several Earths.

== Problems for uniformitarian theories ==

Jupiter's sidereal day is less than ten Earth hours long. If Jupiter formed simply as an accretion aggregate of the [[nebula hypothesis|solar nebula]], then it should not have acquired such tremendous angular momentum. The problem involves not merely the short sidereal day but also Jupiter's tremendous mass.

The alternative theory is that Jupiter formed as a "failed protostar" at the center of its own nebula. This theory has several problems:

# Jupiter never ignited, though its magnetic field is four times as strong as its mass would normally predict.
# None of Jupiter's 63 moons is gaseous. Therefore a key event in the nebular sequence did not take place.
# The four dwarf-planet-sized [[Galilean moons]] have vastly differing apparent geological "ages" coming from times estimated to be as disparate as ten million years to as recent as thirteen hundred (although the times cannot be fixed with any reliability).<ref>Fulbright, Jeannie. ''Exploring Creation with Astronomy.'' Apologia Educational Ministries, 2004.</ref>

== Exploration ==
[[Galileo Galilei]] studied Jupiter extensively and in the process discovered its four largest moons--[[Io]], [[Europa (moon)|Europa]], [[Ganymede]], and [[Callisto]], also known as the [[Galilean moons]]. Many other astronomers studied Jupiter from Earth-bound telescopes for hundreds of years. In the process they discovered twelve of Jupiter's moons and the Great Red Spot, but did not discover Jupiter's ring system.

Seven spacecraft, all from the [[United States]], have visited Jupiter thus far. First to do so was [[Pioneer 10]] (December 3, 1973), which suffered tremendously from the radiation belt but still provided the evidence for Jupiter's [[magnetosphere]]. [[Pioneer 11]] was next (December, 1974) and took far better images of Jupiter and its Great Red Spot.

[[Voyager 1]] (March, 1979) and [[Voyager 2]] (July, 1979) gave the first comprehensive views of Jupiter and the Jovian system, including the discovery of its rings, the discovery of four moons inside [[Io]]'s orbit, and the first extensive studies of the [[Galilean moons]].

[[Ulysses]] (February 1992) made a brief flyby of Jupiter in order to place itself in polar orbit around the Sun. Nevertheless [[European Space Agency]] scientists used this opportunity to make further measurements of Jupiter's magnetosphere and the effect upon it by the solar wind.

[[Galileo Project|Galileo]] reached Jupiter in 1995. It released a probe to dive into Jupiter's atmosphere; that probe transmitted for nearly an hour before the tremendous pressures crushed it. Galileo's orbiter remained in the system for nearly eight years, through two extensions of its mission, and conducted the most extensive surveys of the Galilean moons to day. Eventually, with the craft low on fuel, mission planners dived it into Jupiter to prevent its possibly crashing into [[Europa]], rupturing Europa's ice sheet, and contaminating the liquid ocean that astronomers now suspect lies a mere 10 km deep to the ice and could yet harbor [[extraterrestrial life]].<ref name=nasa3/>

[[Cassini-Huygens Mission|Cassini]] flew by Jupiter briefly in 2000 on its way to [[Saturn]]. While in the Jovian system, it took the image shown at the top of this article.

The [[New Horizons mission]] will include a Jupiter flyby in its journey to the [[Pluto]] system.

== References==
{{reflist|2}}
{{Solarsystem}}

Eris

2015-01-28T00:14:11Z

ScKinney: /* Problem for uniformitarian theories */

: ''This article is about the [[Dwarf Planet]] named Eris. For the classical goddess, see [[Eris (mythology)]]. For any other use, see [[Eris (disambiguation)]].
{{Planet|image=Eris and Dysnomia.jpg
|date=October 21, 2003<ref name=IAU1>"[http://www.cfa.harvard.edu/iau/lists/NumberedMPs.html Discovery Circumstances: Numbered Minor Planets]." [[International Astronomical Union]], Minor Planet Center, May 1, 2007. Accessed May 15, 2008.</ref>
|discname=Michael E. Brown<ref name=IAU1/><ref name=usgs>"[http://planetarynames.wr.usgs.gov/append7.html Gazetteer of Planetary Nomenclature: Planetary Body Names and Discoverers]." US Geological Survey, Jennifer Blue, ed. March 31, 2008. Accessed April 17, 2008.</ref><ref name=Brown2>Brown, M.E., Van Dam, M. A., Bouchez, A. H., Le Mignant, D., ''et al''. "[http://arxiv.org/pdf/astro-ph/0510029 Satellites of the Largest Kuiper Belt Objects]." ''Astrophys. J. Lett.'' 639(L43), October 3, 2005. <arXiv:astro-ph/0510029.> Accessed May 15, 2008.</ref>
|origname=Greek goddess of discord<ref name=usgs/>
|primary=Sun
|order=12
|periapsis=37.93 AU<ref name=johnston>Johnston, William Robert. "[http://www.johnstonsarchive.net/astro/astmoons/am-136199.html Entry for 136199 Eris and Dysnomia]." Johnston Archive, August 21, 2007. Accessed May 15, 2008.</ref>
|apoapsis=97.53 AU<ref name=johnston/>
|semimajor=67.732 AU<ref name=johnston/>
|bode=154 AU<ref name=calc>Calculated</ref>
|eccentricity=0.4400<ref name=johnston/>
|sidereal=557.4 a<ref name=johnston/>
|orbitspeed=3.436 km/s
|inclination=44.1595°<ref name=johnston/>
|reference=the ecliptic
|siderealday=8 h
|mass=1.66 * 1022 kg<ref name=johnston/><ref name=Brown1>Brown, Michael E., and Schaller, Emily L. "[http://www.sciencemag.org/cgi/content/abstract/316/5831/1585 The Mass of Dwarf Planet Eris]." ''Science'', 316(5831):1585, June 15, 2007. <doi:10.1126/science.1139415> Accessed May 15, 2008.</ref><ref name=reitan>Reitan, Kari. "[http://www.nasa.gov/mission_pages/hubble/news/eris.html Astronomers Measure Mass of Largest Dwarf Planet]." Space Telescope Science Institute, [[National Aeronautics and Space Administration]], June 14, 2007. Accessed January 21, 2008.</ref>
|density=2,260 kg/m³<ref name=johnston/>
|surfacegrav=0.6554 m/s²<ref name=calc/>
|escapespeed= 1.305 km/s<ref name=calc/>
|meanradius =1,300 km<ref name=Planck>"[http://www.astro.uni-bonn.de/~bertoldi/ub313/ Comment on the recent Hubble Space Telescope size measurement of 2003 UB313 by Brown et al]." Max Planck Institut für Radioastronomie, April 13, 2006. Accessed May 15, 2008.</ref>
|surfacearea= 21,237,166 km²<ref name=calc/>
|mintemp=30 K
|meantemp=42.5 K
|maxtemp=55 K
|moons=1
|color=white to light gray
|albedo=0.87<ref name=johnston/>
}}'''Eris''', also known as '''Xena''', also known as '''2003 UB313''', the largest of all [[dwarf planet]]s (also classified as a [[Dwarf Planet#Plutoids|plutoid]]), is named for the Greek goddess of discord and strife. Considering the debate that the discovery of this object provoked, the name is probably quite apt.

== Discovery, Naming, and Debate ==
Eris was first photographed on October 21, 2003, but was at first too slow-moving for the Palomar Observatory image-analytic software to detect. Later, [[Michael E. Brown]], [[Chad Trujillo]], and [[David Rabinowitz]] ordered re-analysis of the images with greater sensitivity. They soon realized that the images depicted a new object, and announced their findings on January 5, 2005.

The initial name for the new object was Xena, the title character in an [[United States|American]] [[television]] action-adventure dramatic series,<ref>The character is supposed to be a princess from a tribe of warriors, either Argive or closely allied with them, in the days of the Mycenean civilization, and a contemporary of, and occasional rival to, Hercules. No historical warrant exists for the existence of such a person or even for a classical poem mentioning that name.</ref> and also a name beginning with X, in keeping with the suspicion that this object was the long-sought "Planet X." The object also had a satellite, which the discoverers tentatively named Gabrielle, after the supporting character in that dramatic series.

The announcement of Eris' discovery on July 29, 2005 presented the [[International Astronomical Union]] with an embarrassing problem.<ref name=Hamilton>Hamilton, Calvin J. "[http://www.solarviews.com/eng/eris.htm Entry for 'Eris']." ''Views of the Solar System'', 2007. Accessed January 21, 2008.</ref> Other observations, specifically of the period and orbital characteristics of the satellite,<ref name=Ingham>Ingham, Richard. "[http://www.abc.net.au/science/news/stories/s1560563.htm 'Tenth planet' Xena bigger than Pluto]." Agence France-Presse, quoted by Australian Broadcasting Corporation, February 2, 2006. Accessed May 15, 2008.</ref><ref name=solstation>[http://www.solstation.com/stars/UB313.htm Eris (2003 UB313) and Dysnomia]. Accessed January 22, 2008.</ref> had already suggested that 2003 UB313 might be more massive even than [[Pluto]], then considered the ninth [[planet]] in the [[solar system]]. Because planets and Kuiper-Belt objects have different naming conventions, and because [[scattered disk]] objects had ''no'' naming convention at the time, the names for the new primary and satellite remained unofficial.<ref name=Tytell>Tytell, David. "[http://www.skyandtelescope.com/news/home/3916126.html All Hail Eris and Dysnomia]." ''Sky and Telescope'', September 14, 2006. Accessed May 15, 2008.</ref>

Finally the [[International Astronomical Union]] declared<ref>"[http://www.iau.org/iau0602.423.0.html IAU0602: the Final IAU Resolution on the Definition of 'Planet' Ready for Voting]," ''International Astronomical Union'', 2005. Accessed January 14, 2008.</ref> that Pluto and 2003 UB313 were not planets, but belonged to a new category called [[dwarf planet]]s. Then on September 6, 2006, Mike Brown and his team<ref name=Brown4>Brown, Mike. "[http://www.gps.caltech.edu/%7Embrown/planetlila/index.html The discovery of Eris, the largest known dwarf planet]." California Institute of Technology. Accessed January 22, 2008.</ref> recognized that the name "Xena" was inappropriate for 2003 UB313 and suggested to the IAU that they name it Eris, after the Greek goddess of discord and strife. They also suggested that the IAU name the satellite Dysnomia, for the Greek goddess of lawlessness and daughter of Eris.<ref>Dysnomia, meaning "lawlessness," is also a play on the name of the American actress who portrayed Xena, Lucy Lawless.</ref> Four days later, the IAU oficially named the primary Eris and named its satellite Dysnomia.<ref name=IAU2>[http://cfa-www.harvard.edu/iau/special/08747.pdf IAU Circular No. 8747], International Astronomical Union, September 10, 2006. Accessed May 15, 2008.</ref>

== Orbital characteristics ==
At 67.7 AU from the [[Sun]], it is the most distant object yet discovered that has the [[Sun]] for a primary. At aphelion, it is far beyond the [[Kuiper belt]] and in what is known as the [[scattered disk]] of the [[solar system]]. Because Eris is so distant from [[Earth]] (currently near [[Apsis|aphelion]] and hence three times more distant than is Pluto as of 2008), it has a very long sidereal year of 557 Julian years. Its synodic year is very nearly the same as an [[Earth]] year.

== Surface and atmosphere ==
[[Image:2003 UB313 near-infrared spectrum.jpg|thumb|250px|left|Near infrared spectrum of dwarf planet Eris, taken with the Gemini 8 m telescope.]]Infrared spectroscopic scans of Eris reveal an infrared reflectance spectrum remarkably like that of [[Pluto]], which is known to have a layer of [[methane]] on its surface. From this, the discovery team concludes that Eris is surfaced with solid frozen [[methane]], with rock and [[water]] ice beneath.

Yet Eris is the second most reflective body in the entire solar system, reflecting about 86% of the incident sunlight. Eris is also uniformly white on its surface, whereas Pluto is a mottled brown. The discoverers believe that this is due entirely to Eris' present far-flung position (near aphelion), and point out that Eris' orbit is the most eccentric orbit of any satellite of the [[Sun]], except for [[comet]]s.

== Implications for Other Trans-Neptunian Objects ==
Brown ''et al.'' noted<ref name=Brown2/> in 2005 that Eris, Dysnomia's primary, is one of three of the four brightest Kuiper belt objects that have satellites. (The other two are [[Pluto]] and 2003 EL61.) The fourth, 2005 FY9, has no satellite that Earth-based telescopes can presently detect. Most Kuiper belt objects ''do not'' have satellites, and that three of the four brightest should have satellites suggests that their origins were significantly different from those of other Kuiper belt objects.

== Problem for uniformitarian theories ==
Brown states<ref name=Brown1/> that the near-circular orbit of Dysnomia about Eris actually is consistent with Dysnomia's origin as the result of a collision between Eris and another object.

== Satellites ==
Eris has one known satellite, a tiny moon called [[Dysnomia]]. In classical [[mythology]], Dysnomia is the name given to Eris' daughter, who is a symbol of actual lawlessness.

== Observation and exploration ==
The [[Hubble Space Telescope]] and the Keck Observatory are the first two telescopes to observe the Eridian system. No deep-space missions are planned.

== References ==
{{reflist|2}}

{{solarsystem}}

Mars

2015-01-28T00:11:38Z

ScKinney: /* Satellites */

''For the [[Roman]] god of war, see [[Mars (god)]]''

{{Planet|image=Mars Viking.jpg
|caption=Mars photographed by [[Viking Orbiter]]s
|symbol=Mars symbol.svg
|discname=Known to ancients
|origname=Roman god of war
|order=4
|primary=Sun
|periapsis=206,620,000 km<ref name=marsfact>Williams, David R. "[http://nssdc.gsfc.nasa.gov/planetary/factsheet/marsfact.html Mars Fact Sheet]." National Space Science Data Center, [[National Aeronautics and Space Administration|NASA]], November 29, 2007. Accessed May 27, 2008.</ref>
|apoapsis=249,230,000 km<ref name=marsfact/>
|semimajor=227,920,000 km<ref name=marsfact/>
|bode=1.6 AU
|circumference=1,429,033,627 km
|eccentricity=0.0935<ref name=marsfact/>
|sidereal=686.980 da<ref name=marsfact/>
|synodic=779.94 da<ref name=marsfact/>
|orbitspeed=24.077 km/s
|inclination=1.850°<ref name=marsfact/>
|reference=the ecliptic
|siderealday=24.6229 h<ref name=marsfact/>
|solarday=24.6597 h<ref name=marsfact/>
|rotatespeed=465.11 m/s
|axialtilt=25.19°<ref name=marsfact/>
|mass=6.4185 * 1023 kg<ref name=marsfact/>
|density=3,933 kg/m³<ref name=marsfact/>
|surfacegrav=3.71 m/s²<ref name=marsfact/>
|escapespeed=5.03 km/s<ref name=marsfact/>
|meanradius=3389.5 km<ref name=marsfact/>
|equatorradius =3396.2 km<ref name=marsfact/>
|polarradius=3376.2 km<ref name=marsfact/>
|surfacearea=144,800,000 km²
|mintemp=140 K<ref name=Arnett>Arnett, Bill. "[http://www.nineplanets.org/mars.html Entry for Mars]." ''The <s>Nine</s> 8 Planets'', September 26, 2006. Accessed May 27, 2008.</ref>
|meantemp=218 K<ref name=Arnett/>
|maxtemp=300 K<ref name=Arnett/>
|moons=2
|composition=Rock
|color=Red
|albedo=0.15<ref name=marsfact/>
|pmdm=2.1 * 1018 N-m/T<ref name=Humphreys>Humphreys, D. R. "[http://www.creationresearch.org/crsq/articles/21/21_3/21_3.html The Creation of Planetary Magnetic Fields]." ''[[Creation Research Society Quarterly]]'' 21(3), December 1984. Accessed April 29, 2008.</ref>
|cmdm=1.51 * 1023 N-m/T<ref name=Humphreys/>
|mdt=535 a<ref name=Humphreys/>
|mhl=370.83 a<ref name=calc>Calculated</ref>
}}
'''Mars''' is the fourth planet from the [[Sun]], after [[Mercury]], [[Venus]], and [[Earth]]. It is called "The Red Planet" on account of the [[iron oxide]] that covers much of its suface.

== Ancient knowledge and naming ==
Mars has the [[Rome|Roman]] name of the classical god of war. This name in turn derives from the [[Greece|Greek]] name ''Ares'' for this god. (The traditional symbol of Mars is his shield and spear.) The ancient [[Egypt]]ians simply called Mars ''Her Descher'', or "the red one."<ref name=Hamilton>Hamilton, Calvin J. "[http://www.solarviews.com/eng/mars.htm Entry for Mars]." ''Views on the Solar System'', 2008. Accessed May 27, 2008.</ref> The [[Hindu]]s call Mars Mangala, one of the Navagraha.<ref name=ucar>"[http://www.windows.ucar.edu/tour/link=/mythology/mangala.html&edu=high Mangala]." ''Windows to the Universe'', University Corporation for Atmospheric Research, University of Michigan, September, 2000. Accessed May 27, 2008.</ref> The [[Maya]] people also tracked Mars regularly.

== Orbital characteristics ==
Mars is in a slightly elliptical orbit around the Sun and maintains an average distance slightly more than 1.5 AU. The synodic period of Mars is roughly 26 months. This fact makes transfer windows to Mars more common than those to slower-orbiting object, such as Jupiter and Saturn.

== Rotational characteristics ==
Mars' sidereal and solar days are only slightly longer than the days of earth. This fact has led long-term Mars mission planners to adopt a permanent system for keeping time "local" to Mars. The first mission to use this "Mars solar clock" was [[Viking 1]] in 1976.<ref name=Allison>Allison, Michael, and Schmunk, Robert. "[http://www.giss.nasa.gov/tools/mars24/help/notes.html Technical Notes on Mars Solar Time as Adopted by the Mars24 Sunclock]." Goddard Institute for Space Studies, [[National Aeronautics and Space Administration|NASA]], May 20, 2008. Accessed May 27, 2008.</ref>

== Physical characteristics ==
Mars is half the size of Earth and has about 11% of earth's mass. The large proportion of [[iron]] in Mars' clay-like topsoil gives Mars its distinctive color.

The weather on Mars is seasonal, on account of Mars's axial inclination. Yet because Mars's orbit is so eccentric, "summer" and "winter" on the northern and southern hemispheres can vary greatly. Temperatures vary from 140 K to 300 K, with an average temperature of 210 K. (The freezing point of [[water]] is 273.15 K.)

=== Atmosphere ===
Mars' atmosphere is quite thin and has an average pressure of 6.36 mb or 0.636% of that of earth. Its chief components are 95.32% [[carbon dioxide]], 2.7% [[nitrogen]], 1.6% [[argon]], 0.13% [[oxygen]], and 0.08% [[carbon monoxide]]. In addition it has trace amounts of [[water]] (210 ppm), [[nitrogen oxide]] (100 ppm), [[neon]] (2.5 ppm), hydrogen-deuterium oxide (HDO) (0.85 ppm), [[krypton]] (0.3 ppm), and [[xenon]] (0.08 ppm). Winds on Mars vary in speed from 2-7 m/s in summer to 5-10 m/s in fall, though the [[Project Viking]] landers have recorded winds varying from 17-30 m/s during dust storms that have swept past the landing sites.<ref name=marsfact/>

Recent warming trends on Mars, including an apparent partial melt of the polar ice caps, have led at least one scientist to question the widely circulating theories of [[global warming]] on earth. Specifically, Habibullo Abdussamatov, head of space research at St. Petersburg's Pulkovo Astronomical Observatory in Russia, asserts that the sun, and not any activity specific to the earth, must be responsible for any warming observed on either planet.<ref name=ngs>Ravilious, Kate. "[http://news.nationalgeographic.com/news/2007/02/070228-mars-warming.html Mars Melt Hints at Solar, Not Human, Cause for Warming, Scientist Says]." ''National Geographic News'', National Geographic Society, February 28, 2007. Accessed May 27, 2008.</ref>

=== Magnetosphere ===
Mars has a very weak magnetic field. Data from various missions has established an upper limit of 2.1 * 1018 N-m/T on the [[magnetic dipole moment]] of Mars. According to [[Russell Humphreys]]'s model of the creation of magnetic fields, Mars probably had a magnetic dipole moment ''at creation'' of 1.51 * 1023 N-m/T. Thus Mars's magnetic field has been decaying very rapidly. This tremendous decay, and the presence on [[Mercury]] of a magnetic field of significant strength, baffles [[astronomy|astronomers]] who have assumed that magnetic fields form on rapidly moving planets that have conductive and liquid cores that can act as dynamos. In fact, Humphreys asserts that the characteristic that determines which of the [[Terrestrial Planet|terrestrial planets]] will have a persistent magnetic field is the core radius, and that the cores of all four of these planets have similar conductivities. Mercury and Earth have larger cores than do Mars and Venus. The lengths of the sidereal days on those worlds do not matter.<ref name=Humphreys/>

=== Geology ===
[[Image:MarsTopoMap-PIA02031 modest.jpg|left|thumb|300px|Topographic map of Mars.]]
There is a dichotomy on the surface of Mars; the northern hemisphere consists of low-lying volcanic plains, with the southern hemisphere consists of ancient, heavily-cratered highland plains. Mars also has two volcanic regions: Tharsis and Elysium. Within the Tharsis region is the largest volcano in the solar system, [[Olympus Mons]]. Olympus Mons is approximately 500 km across and is about the same size as the state of Arizona. Its peak is 24 km above the surrounding plains and it is surrounded by a vertical scarp 6 km high. A large canyon system, Valles Marineris, is located along the Martian equator east of the Tharsis region. Valles Marineris is 2-6km deep and 200-600km wide and approximately 4,500 km long (approximately the distance from San Francisco to Boston). The eastern part of Valles Marineris appears to have a tectonic origin, but the western part is characterized by features such as teardrop islands and longitudinal grooves, indicating it may have been formed by catastrophic flooding in the past. Such flooding may be possible under current climate conditions. Run-off channels in the cratered highland indicate a thicker atmosphere or warmer climate in the past that would have allowed water to be stable on the surface.

Recent satellite imagery has shown that Mars has a 3 kilometre deep ice cap around its polar regions. The northern polar region is surrounded by [[dune]] fields. During the Martian winter, a layer of carbon dioxide condenses at the poles and sublimates in the summer, leaving the water-ice and dust polar caps exposed. The ratio of dust to water-ice contained in the polar caps remains unknown.
[[Image:F035a72_processed.jpg|thumb|100px|left|Cydonia Mensae, home of the alleged "face on Mars."]]
Persistent rumors tell of a "face on Mars," allegedly located in the Cydonia Mensae region at coordinates 40.9°N and 9.45°W. This alleged "face" is located in the midst of several pyramids and other mountains. Prevailing opinion at NASA is that the "face" is a [[pareidolia|trick of the eye]] due to the unusual lighting conditions.<ref name=faq>Williams, David R. "[http://nssdc.gsfc.nasa.gov/planetary/planetaryfaq.html#Mars Frequently Asked Questions - Planetary - Mars]." National Space Science Data Center, [[National Aeronautics and Space Administration|NASA]], January 2, 2008. Accessed May 27, 2008.</ref>

=== Water on Mars ===
[[Image:Weeping_100.jpg|thumb|120px|right|Multiple gullies in a south-facing wall in the Gorgonum Chaos region on Mars]]
Mars cannot have liquid water on its surface. The thin atmosphere does not permit this, even during high summer on Mars. Yet the [[Mars Global Surveyor]] mission in June 2000 took photographs of gully-like formations on several precipices and crater walls on Mars. These formations tend to occur between 30° and 70° north and south latitude. Mission analysts further suggest that these formations are relatively fresh and estimate that liquid water might be found less than 500 meters beneath the surface.<ref name=msss>"[http://www.msss.com/mars_images/moc/june2000/ MOC Images Suggest Recent Sources of Liquid Water on Mars]." Malin Space Science Systems, June 22, 2000. Accessed May 27, 2008.</ref>

More recently, NASA's latest mission, the [[Phoenix lander]], has discovered what appears to be water ice very near the surface near Mars' north pole. Furthermore, analysis of a cubic meter of soil at this site reveals that the soil is far more [[alkali]]ne than expected, and has tolerable levels of salt and low levels of [[calcium]]. Investigators have even suggested that the soil might support the growth of an Earth vegetable, like [[asparagus]],<ref name=courier>"[http://www.news.com.au/couriermail/story/0,23739,23932393-5013016,00.html Scientists find soil on Mars good enough to grow asparagus]." ''The Courier Mail'', June 28, 2008. Accessed June 30, 2008.</ref> if not for the fact that the atmosphere is too thin for water to be a liquid.

== Life on Mars ==
The possibility that [[extraterrestrial life]] exists, or has existed, on Mars has been the subject of persistent scientific speculation for decades. The earliest speculation concerned a possible civilization on Mars,<ref name=Hamilton/> this after Percival Lowell theorized that the straight lines that several astronomers had seen on Mars were in fact artificial constructs, and specifically canals.<ref name=canals>"[http://ssed.gsfc.nasa.gov/tharsis/canals.html The canals of Mars--historical note]." Goddard Space Flight Center, [[National Aeronautics and Space Administration|NASA]], n.d. Accessed May 27, 2008.</ref> Lovell popularized his theory as early as 1906, and for a long time the suspicion of a non-human civilization native to Mars would find repeated expression in novels and dramatic presentations. Only with the first successful explorations of Mars would the scientific community, and the public, abandon that theory.

Current speculation concerns the possible finding of [[microbe]]s. These would be [[extremophile]]s, or microbes that survive and even grow in environments lethal to other forms of life. Direct attempts to find such life began in 1976 with the [[Viking 1]] and [[Viking 2]] landers. To date no positive sign of life on Mars has been found. The Viking landers found evidence of unexplained chemical activity, but no clear evidence of microbes. Whether the Viking landers would have been able to detect extremophiles, a concept unknown to the Viking mission planners, is unclear.<ref name=Hamilton/>

The [[astrobiology|astrobiologists]] involved with [[Project Viking]] suspect that Mars might be an inherently inhospitable environment for life. Ultraviolet light from the sun shines unchecked on Mars, on account of Mars' thin atmosphere and weak magnetic field. The soil of Mars is also very dry, and the soil has a high proportion of oxidizing agents.<ref name=Hamilton/>

== Problem for uniformitarian theories ==
The most formidable current problem that Mars poses for uniformitarians today is that its magnetic field is weak and inconsequential, while a planet (Mercury) of little more than half its weight does have a significant magnetic field. According to current theory, planets derive their magnetic fields by dynamo action. This requires fast rotation and liquid cores. Mars and Earth have comparable sidereal days, but Earth's magnetic field is strong enough to protect Earth from the [[solar wind]], while that of Mars is not. Mercury has a far longer sidereal day than Mars has, and yet Mercury has a significant magnetic field while Mars has none.

== Young Mars Creation model. ==
[[Image:Meridiani Planum.jpg|thumb|150px|right|Meridiani Planum region of Mars.]]

Discoveries by the [[Mars Excursion Rover]] ''Opportunity'' have led to a Young Mars Creation model of Martian geology. These discoveries combine with data from the rest of Mars to indicate a massive Martian catastrophe.

Since ''Opportunity'' landed in the Meridiani Planum region of Mars it has sent back findings showing that the area was once underwater and that the water was very acidic. This high concentration of [[sulfuric acid]] militates against this being a habitable sea. The entire Meridiani Planum region has much evidence of catastrophic flooding, including a clear inlet channel to the southeast and a splash zone in the north.

Mars contains the largest of three major geologic features in the Solar System. The largest impact basin, the largest volcanoes and the largest canyon are all found on Mars and in a clear relationship to each other. This relationship provides the key to understanding Martian geology.

[[Image:Mars topography.jpg|thumb|150px|right|Mars' global topography, and the relationship between the Hellas impact basin and the Tharsis volcanoes.]]Mars’ largest impact basin is called Hellas. As shown in the topography map, on exactly the other side of Mars from Hellas is Mount Alba Patera, the largest volcano by surface area. This antipodal juxtaposition suggests that the Hellas impact caused the eruptions of Alba Patera and the volcanoes of the Tharsis plateau to the south and southwest. To the east is found the gigantic rift valley called Valles Marineris.

These relationships indicate a major geologic catastrophe on Mars resulting in massive volcanic activity. The dating of this event from craters places it at about the time of the [[Great Flood]] on [[Earth]]. This volcanic activity would have increased Mars’s atmospheric pressure to allow liquid water to flow on the surface and thus allow the flooding of the Meridiani Planum region.

This shows that, like Earth, Mars has evidence that it is only a few thousands of years old and not 4.6 billion years old.<ref name=creager>Creager, Charles, Jr. "[http://www.answersingenesis.org/articles/arj/v1/n1/mars-testament-catastrophe Mars, a Testament to Catastrophe]." ''Answers Research Journal'' 1 (2008): 89–93. Accessed September 23, 2008.</ref>

== Mars in popular culture ==
Mars has figured prominently in [[science fiction]] in the Western world for more than a century.

=== The War of the Worlds ===
The first novel speculating on a civilization on Mars was ''The War of the Worlds'' by [[H. G. Wells]], in 1897. Wells' Martians had a military strength that human civilization could not match, but ultimately perished after contracting various [[infectious disease]]s caused by microbes native to Earth to which the Martians effectively had no defense.

In 1938, actor/director [[Orson Welles]] and his Mercury Theater produced a [[radio]] drama based on this novel. Welles updated the novel to his own period but otherwise remained faithful to the source material. The broadcast created such a panic in the [[United States]] that Welles was compelled to order a broadcast disclaimer in mid-show and, at the end of the show, personally assure his listeners that no such thing as an extraterrestrial invasion had taken place.<ref name=Hamilton/>

H. G. Wells' novel would inspire two [[motion picture]] projects and one [[television]] series.

=== Other speculations on civilizations ===
Author [[Edgar Rice Burroughs]] published several novels speculating on an elaborate civilization on Mars to which humans traveled, but which was not bent on invading the earth. Author [[C. S. Lewis]], in his novel ''Out of the Silent Planet'', envisioned Mars as the home of three races of non-fallen beings that were instructed to regard the earth as off-limits on account of man's [[fall of man|fallen nature]].

With the abandonment of the Lowell canal theory, science fiction authors and dramatists envisioned Mars as home to a human colony, such as the situation in the television series ''[[Terrahawks]]''. But at least one motion-picture producer saw Mars as a place that very ancient [[astronaut]]s had once visited. These astronauts, according to this scenario, left behind some advanced equipment that a human rebel was subsequently able to use to give Mars a breathable atmosphere and thus facilitate the Martian colony's liberation from the civilization of earth, which in the story had become venal and tyrannical.

=== Speculation on microbes ===
Authors [[John B. Olson]] and [[Randall S. Ingermanson]] have recently speculated (''[[Oxygen (novel)|Oxygen]]'' and ''[[The Fifth Man]]'') about the finding of microbes on Mars, and the implications that such a discovery would hold for the [[Christianity|Christian]] faith and the possible "back-contamination" of the earth when the crew that found the microbes returned to earth.

== Observation and exploration ==
Observation of Mars has been ongoing since the ancients noted its existence and its movements. The invention of the telescope provoked the first serious study of Mars as a celestial object, and not a prophetic sign. Yet not all of this observation led to proper inferences. Percival Lowell's canal theory would lead to more than half a century of vain speculation on extraterrestrial civilization before the first successful exploratory missions would return evidence forcing the abandonment of that theory.

Mars has been the subject of more attempts to explore it, and more failures, than any other planet. Of approximately 37 separate missions to Mars, only 13 have had any success. The planetary scientists of the [[Union of Soviet Socialist Republics]], so successful in exploring [[Venus]], experienced ten mission failures before achieving their first success, seven years after the [[United States]] achieved success with its [[Mariner 4]] mission. That Soviet mission, [[Mars 3]] in 1971, succeeded in placing a lander on Mars, but the lander's system transmitted for only 20 seconds before failing.

In 1975, [[Project Viking]] achieved the most notable success by placing two orbiters and two landers on Mars. Neither nation would attempt any further missions to Mars until 1988, when the Soviets lost one craft en route and lost contact with the other ([[Phobos 2]] seconds after its rendezvous with Mars's inner [[moon]] [[Phobos]]. Nor was the United States' program immune to failure; its ''Mars Observer'' vessel was lost prior to arrival after some propulsion systems failed.<ref name=faq/>

In 1996 the [[Mars Global Surveyor]] enjoyed the most success to date, returning more images than all previous missions combined. In that same year, the United States landed the first mobile explorer, or "rover," called the [[Mars Pathfinder]].

The United States would, unfortunately, lose the next two successive craft that it sent to Mars. But its [[Mars Odyssey]] would arrive intact in 2001 and send back the first high-resolution images. Two years later the [[European Space Agency]] would successfully place its [[Mars Express]] orbiter in the Martian system; sadly, its associated landing craft would crash-land. The Mars Express orbiter continues in orbit around Mars.<ref name=esa>"[http://www.esa.int/SPECIALS/Mars_Express/ Mars Express home page]." European Space Agency. Accessed May 27, 2008.</ref>

[[Image:Mcmurdopan_spirit_big.jpg|thumb|left|150px||360 degree panorama from mars rover ''Spirit''.]]
The most successful missions to date have been the Mars Excursion Rover missions. Two of these sophisticated mobile robots, named ''Spirit'' and ''Opportunity'', launched in 2003 and arrived safely on Mars about six months later, on opposite sides of the planet. They have been running for four years now, at least fifteen times longer than they were warranted to run. The Opportunity rover has been taking pictures of the Victoria Crater, and Spirit has been photographing the Esperanza formation which contains "vesicular" basalt (characterized by multiple cavities representing dissolved gas escaping from solution during a volcanic eruption).<ref name=David>David, Leonard. "[http://www.space.com/missionlaunches/061228_rovers_update.html Mars Rovers: On the Roll to New Targets]." ''Space.com'' December 28, 2006. Accessed May 27, 2008.</ref>

On May 26, 2008, NASA placed a polar lander on Mars for the first time: the [[Phoenix lander]]. As of June 28, 2008, the Phoenix lander is functioning well and has already discovered water ice where it landed. Contrary to prior understandings, the Phoenix lander has found an alkaline soil that might be suitable for growing Earth vegetables.

At least one non-governmental group, calling itself the Mars Society, has been actively studying technologies appropriate to send a crew of from four to six astronauts to Mars for a roughly two-year stay.<ref name=marssoc>[http://www.marssociety.org/portal The Mars Society] global and USA portal. Accessed May 27, 2008.</ref>

In 2012 a rover named "Curiosity" landed on Mars. It is the first Martian lander to use RTGs (Radioisotope thermoelectric generators) instead of solar panels.

==Satellites==
Mars has two moons: [[Phobos]] and [[Deimos]] (which respectively mean "Fear and "Panic" in [[Greek language|Greek]]). Russian scientists in the 1950s posited that Phobos might be hollow, but these claims were discredited in the late 1960s. The orbit of Phobos is slowly shrinking, and it will impact Mars in several million years.

== References ==
{{reflist|2}}

== Related Links ==
* [http://mars.jpl.nasa.gov/missions/log/ NASA Historical Log: Missions to Mars]
* [http://www.space.com/mars/ Space.com] All About Mars
* [http://www.google.com/mars/ Google Mars], an interactive topographical map
* [http://starchild.gsfc.nasa.gov/docs/StarChild/solar_system_level2/mars.html Mars: the Red Planet] by Starchild, an educational service of NASA.
* [http://www.war-of-the-worlds.org/ War of the Worlds] commemorative site.
* [http://www.solarviews.com/eng/terms.htm Glossary]
* [http://www.answersingenesis.org/articles/arj/v1/n1/mars-testament-catastrophe Mars, a Testament to Catastrophe]
* [http://www.youtube.com/watch?v=BnOhFXamYOc Catastrophic Model of Martian Geology I] Video
* [http://www.youtube.com/watch?v=6HwZ22eYhAg Catastrophic Model of Martian Geology II]Video
*[http://genesismission.4t.com/Video/Mars1.html Catastrophic Model of Martian Geology] With Video

{{solarsystem}}
[[Category:Mars]]

Mars

2015-01-28T00:10:34Z

ScKinney: /* Observation and exploration */

''For the [[Roman]] god of war, see [[Mars (god)]]''

{{Planet|image=Mars Viking.jpg
|caption=Mars photographed by [[Viking Orbiter]]s
|symbol=Mars symbol.svg
|discname=Known to ancients
|origname=Roman god of war
|order=4
|primary=Sun
|periapsis=206,620,000 km<ref name=marsfact>Williams, David R. "[http://nssdc.gsfc.nasa.gov/planetary/factsheet/marsfact.html Mars Fact Sheet]." National Space Science Data Center, [[National Aeronautics and Space Administration|NASA]], November 29, 2007. Accessed May 27, 2008.</ref>
|apoapsis=249,230,000 km<ref name=marsfact/>
|semimajor=227,920,000 km<ref name=marsfact/>
|bode=1.6 AU
|circumference=1,429,033,627 km
|eccentricity=0.0935<ref name=marsfact/>
|sidereal=686.980 da<ref name=marsfact/>
|synodic=779.94 da<ref name=marsfact/>
|orbitspeed=24.077 km/s
|inclination=1.850°<ref name=marsfact/>
|reference=the ecliptic
|siderealday=24.6229 h<ref name=marsfact/>
|solarday=24.6597 h<ref name=marsfact/>
|rotatespeed=465.11 m/s
|axialtilt=25.19°<ref name=marsfact/>
|mass=6.4185 * 1023 kg<ref name=marsfact/>
|density=3,933 kg/m³<ref name=marsfact/>
|surfacegrav=3.71 m/s²<ref name=marsfact/>
|escapespeed=5.03 km/s<ref name=marsfact/>
|meanradius=3389.5 km<ref name=marsfact/>
|equatorradius =3396.2 km<ref name=marsfact/>
|polarradius=3376.2 km<ref name=marsfact/>
|surfacearea=144,800,000 km²
|mintemp=140 K<ref name=Arnett>Arnett, Bill. "[http://www.nineplanets.org/mars.html Entry for Mars]." ''The <s>Nine</s> 8 Planets'', September 26, 2006. Accessed May 27, 2008.</ref>
|meantemp=218 K<ref name=Arnett/>
|maxtemp=300 K<ref name=Arnett/>
|moons=2
|composition=Rock
|color=Red
|albedo=0.15<ref name=marsfact/>
|pmdm=2.1 * 1018 N-m/T<ref name=Humphreys>Humphreys, D. R. "[http://www.creationresearch.org/crsq/articles/21/21_3/21_3.html The Creation of Planetary Magnetic Fields]." ''[[Creation Research Society Quarterly]]'' 21(3), December 1984. Accessed April 29, 2008.</ref>
|cmdm=1.51 * 1023 N-m/T<ref name=Humphreys/>
|mdt=535 a<ref name=Humphreys/>
|mhl=370.83 a<ref name=calc>Calculated</ref>
}}
'''Mars''' is the fourth planet from the [[Sun]], after [[Mercury]], [[Venus]], and [[Earth]]. It is called "The Red Planet" on account of the [[iron oxide]] that covers much of its suface.

== Ancient knowledge and naming ==
Mars has the [[Rome|Roman]] name of the classical god of war. This name in turn derives from the [[Greece|Greek]] name ''Ares'' for this god. (The traditional symbol of Mars is his shield and spear.) The ancient [[Egypt]]ians simply called Mars ''Her Descher'', or "the red one."<ref name=Hamilton>Hamilton, Calvin J. "[http://www.solarviews.com/eng/mars.htm Entry for Mars]." ''Views on the Solar System'', 2008. Accessed May 27, 2008.</ref> The [[Hindu]]s call Mars Mangala, one of the Navagraha.<ref name=ucar>"[http://www.windows.ucar.edu/tour/link=/mythology/mangala.html&edu=high Mangala]." ''Windows to the Universe'', University Corporation for Atmospheric Research, University of Michigan, September, 2000. Accessed May 27, 2008.</ref> The [[Maya]] people also tracked Mars regularly.

== Orbital characteristics ==
Mars is in a slightly elliptical orbit around the Sun and maintains an average distance slightly more than 1.5 AU. The synodic period of Mars is roughly 26 months. This fact makes transfer windows to Mars more common than those to slower-orbiting object, such as Jupiter and Saturn.

== Rotational characteristics ==
Mars' sidereal and solar days are only slightly longer than the days of earth. This fact has led long-term Mars mission planners to adopt a permanent system for keeping time "local" to Mars. The first mission to use this "Mars solar clock" was [[Viking 1]] in 1976.<ref name=Allison>Allison, Michael, and Schmunk, Robert. "[http://www.giss.nasa.gov/tools/mars24/help/notes.html Technical Notes on Mars Solar Time as Adopted by the Mars24 Sunclock]." Goddard Institute for Space Studies, [[National Aeronautics and Space Administration|NASA]], May 20, 2008. Accessed May 27, 2008.</ref>

== Physical characteristics ==
Mars is half the size of Earth and has about 11% of earth's mass. The large proportion of [[iron]] in Mars' clay-like topsoil gives Mars its distinctive color.

The weather on Mars is seasonal, on account of Mars's axial inclination. Yet because Mars's orbit is so eccentric, "summer" and "winter" on the northern and southern hemispheres can vary greatly. Temperatures vary from 140 K to 300 K, with an average temperature of 210 K. (The freezing point of [[water]] is 273.15 K.)

=== Atmosphere ===
Mars' atmosphere is quite thin and has an average pressure of 6.36 mb or 0.636% of that of earth. Its chief components are 95.32% [[carbon dioxide]], 2.7% [[nitrogen]], 1.6% [[argon]], 0.13% [[oxygen]], and 0.08% [[carbon monoxide]]. In addition it has trace amounts of [[water]] (210 ppm), [[nitrogen oxide]] (100 ppm), [[neon]] (2.5 ppm), hydrogen-deuterium oxide (HDO) (0.85 ppm), [[krypton]] (0.3 ppm), and [[xenon]] (0.08 ppm). Winds on Mars vary in speed from 2-7 m/s in summer to 5-10 m/s in fall, though the [[Project Viking]] landers have recorded winds varying from 17-30 m/s during dust storms that have swept past the landing sites.<ref name=marsfact/>

Recent warming trends on Mars, including an apparent partial melt of the polar ice caps, have led at least one scientist to question the widely circulating theories of [[global warming]] on earth. Specifically, Habibullo Abdussamatov, head of space research at St. Petersburg's Pulkovo Astronomical Observatory in Russia, asserts that the sun, and not any activity specific to the earth, must be responsible for any warming observed on either planet.<ref name=ngs>Ravilious, Kate. "[http://news.nationalgeographic.com/news/2007/02/070228-mars-warming.html Mars Melt Hints at Solar, Not Human, Cause for Warming, Scientist Says]." ''National Geographic News'', National Geographic Society, February 28, 2007. Accessed May 27, 2008.</ref>

=== Magnetosphere ===
Mars has a very weak magnetic field. Data from various missions has established an upper limit of 2.1 * 1018 N-m/T on the [[magnetic dipole moment]] of Mars. According to [[Russell Humphreys]]'s model of the creation of magnetic fields, Mars probably had a magnetic dipole moment ''at creation'' of 1.51 * 1023 N-m/T. Thus Mars's magnetic field has been decaying very rapidly. This tremendous decay, and the presence on [[Mercury]] of a magnetic field of significant strength, baffles [[astronomy|astronomers]] who have assumed that magnetic fields form on rapidly moving planets that have conductive and liquid cores that can act as dynamos. In fact, Humphreys asserts that the characteristic that determines which of the [[Terrestrial Planet|terrestrial planets]] will have a persistent magnetic field is the core radius, and that the cores of all four of these planets have similar conductivities. Mercury and Earth have larger cores than do Mars and Venus. The lengths of the sidereal days on those worlds do not matter.<ref name=Humphreys/>

=== Geology ===
[[Image:MarsTopoMap-PIA02031 modest.jpg|left|thumb|300px|Topographic map of Mars.]]
There is a dichotomy on the surface of Mars; the northern hemisphere consists of low-lying volcanic plains, with the southern hemisphere consists of ancient, heavily-cratered highland plains. Mars also has two volcanic regions: Tharsis and Elysium. Within the Tharsis region is the largest volcano in the solar system, [[Olympus Mons]]. Olympus Mons is approximately 500 km across and is about the same size as the state of Arizona. Its peak is 24 km above the surrounding plains and it is surrounded by a vertical scarp 6 km high. A large canyon system, Valles Marineris, is located along the Martian equator east of the Tharsis region. Valles Marineris is 2-6km deep and 200-600km wide and approximately 4,500 km long (approximately the distance from San Francisco to Boston). The eastern part of Valles Marineris appears to have a tectonic origin, but the western part is characterized by features such as teardrop islands and longitudinal grooves, indicating it may have been formed by catastrophic flooding in the past. Such flooding may be possible under current climate conditions. Run-off channels in the cratered highland indicate a thicker atmosphere or warmer climate in the past that would have allowed water to be stable on the surface.

Recent satellite imagery has shown that Mars has a 3 kilometre deep ice cap around its polar regions. The northern polar region is surrounded by [[dune]] fields. During the Martian winter, a layer of carbon dioxide condenses at the poles and sublimates in the summer, leaving the water-ice and dust polar caps exposed. The ratio of dust to water-ice contained in the polar caps remains unknown.
[[Image:F035a72_processed.jpg|thumb|100px|left|Cydonia Mensae, home of the alleged "face on Mars."]]
Persistent rumors tell of a "face on Mars," allegedly located in the Cydonia Mensae region at coordinates 40.9°N and 9.45°W. This alleged "face" is located in the midst of several pyramids and other mountains. Prevailing opinion at NASA is that the "face" is a [[pareidolia|trick of the eye]] due to the unusual lighting conditions.<ref name=faq>Williams, David R. "[http://nssdc.gsfc.nasa.gov/planetary/planetaryfaq.html#Mars Frequently Asked Questions - Planetary - Mars]." National Space Science Data Center, [[National Aeronautics and Space Administration|NASA]], January 2, 2008. Accessed May 27, 2008.</ref>

=== Water on Mars ===
[[Image:Weeping_100.jpg|thumb|120px|right|Multiple gullies in a south-facing wall in the Gorgonum Chaos region on Mars]]
Mars cannot have liquid water on its surface. The thin atmosphere does not permit this, even during high summer on Mars. Yet the [[Mars Global Surveyor]] mission in June 2000 took photographs of gully-like formations on several precipices and crater walls on Mars. These formations tend to occur between 30° and 70° north and south latitude. Mission analysts further suggest that these formations are relatively fresh and estimate that liquid water might be found less than 500 meters beneath the surface.<ref name=msss>"[http://www.msss.com/mars_images/moc/june2000/ MOC Images Suggest Recent Sources of Liquid Water on Mars]." Malin Space Science Systems, June 22, 2000. Accessed May 27, 2008.</ref>

More recently, NASA's latest mission, the [[Phoenix lander]], has discovered what appears to be water ice very near the surface near Mars' north pole. Furthermore, analysis of a cubic meter of soil at this site reveals that the soil is far more [[alkali]]ne than expected, and has tolerable levels of salt and low levels of [[calcium]]. Investigators have even suggested that the soil might support the growth of an Earth vegetable, like [[asparagus]],<ref name=courier>"[http://www.news.com.au/couriermail/story/0,23739,23932393-5013016,00.html Scientists find soil on Mars good enough to grow asparagus]." ''The Courier Mail'', June 28, 2008. Accessed June 30, 2008.</ref> if not for the fact that the atmosphere is too thin for water to be a liquid.

== Life on Mars ==
The possibility that [[extraterrestrial life]] exists, or has existed, on Mars has been the subject of persistent scientific speculation for decades. The earliest speculation concerned a possible civilization on Mars,<ref name=Hamilton/> this after Percival Lowell theorized that the straight lines that several astronomers had seen on Mars were in fact artificial constructs, and specifically canals.<ref name=canals>"[http://ssed.gsfc.nasa.gov/tharsis/canals.html The canals of Mars--historical note]." Goddard Space Flight Center, [[National Aeronautics and Space Administration|NASA]], n.d. Accessed May 27, 2008.</ref> Lovell popularized his theory as early as 1906, and for a long time the suspicion of a non-human civilization native to Mars would find repeated expression in novels and dramatic presentations. Only with the first successful explorations of Mars would the scientific community, and the public, abandon that theory.

Current speculation concerns the possible finding of [[microbe]]s. These would be [[extremophile]]s, or microbes that survive and even grow in environments lethal to other forms of life. Direct attempts to find such life began in 1976 with the [[Viking 1]] and [[Viking 2]] landers. To date no positive sign of life on Mars has been found. The Viking landers found evidence of unexplained chemical activity, but no clear evidence of microbes. Whether the Viking landers would have been able to detect extremophiles, a concept unknown to the Viking mission planners, is unclear.<ref name=Hamilton/>

The [[astrobiology|astrobiologists]] involved with [[Project Viking]] suspect that Mars might be an inherently inhospitable environment for life. Ultraviolet light from the sun shines unchecked on Mars, on account of Mars' thin atmosphere and weak magnetic field. The soil of Mars is also very dry, and the soil has a high proportion of oxidizing agents.<ref name=Hamilton/>

== Problem for uniformitarian theories ==
The most formidable current problem that Mars poses for uniformitarians today is that its magnetic field is weak and inconsequential, while a planet (Mercury) of little more than half its weight does have a significant magnetic field. According to current theory, planets derive their magnetic fields by dynamo action. This requires fast rotation and liquid cores. Mars and Earth have comparable sidereal days, but Earth's magnetic field is strong enough to protect Earth from the [[solar wind]], while that of Mars is not. Mercury has a far longer sidereal day than Mars has, and yet Mercury has a significant magnetic field while Mars has none.

== Young Mars Creation model. ==
[[Image:Meridiani Planum.jpg|thumb|150px|right|Meridiani Planum region of Mars.]]

Discoveries by the [[Mars Excursion Rover]] ''Opportunity'' have led to a Young Mars Creation model of Martian geology. These discoveries combine with data from the rest of Mars to indicate a massive Martian catastrophe.

Since ''Opportunity'' landed in the Meridiani Planum region of Mars it has sent back findings showing that the area was once underwater and that the water was very acidic. This high concentration of [[sulfuric acid]] militates against this being a habitable sea. The entire Meridiani Planum region has much evidence of catastrophic flooding, including a clear inlet channel to the southeast and a splash zone in the north.

Mars contains the largest of three major geologic features in the Solar System. The largest impact basin, the largest volcanoes and the largest canyon are all found on Mars and in a clear relationship to each other. This relationship provides the key to understanding Martian geology.

[[Image:Mars topography.jpg|thumb|150px|right|Mars' global topography, and the relationship between the Hellas impact basin and the Tharsis volcanoes.]]Mars’ largest impact basin is called Hellas. As shown in the topography map, on exactly the other side of Mars from Hellas is Mount Alba Patera, the largest volcano by surface area. This antipodal juxtaposition suggests that the Hellas impact caused the eruptions of Alba Patera and the volcanoes of the Tharsis plateau to the south and southwest. To the east is found the gigantic rift valley called Valles Marineris.

These relationships indicate a major geologic catastrophe on Mars resulting in massive volcanic activity. The dating of this event from craters places it at about the time of the [[Great Flood]] on [[Earth]]. This volcanic activity would have increased Mars’s atmospheric pressure to allow liquid water to flow on the surface and thus allow the flooding of the Meridiani Planum region.

This shows that, like Earth, Mars has evidence that it is only a few thousands of years old and not 4.6 billion years old.<ref name=creager>Creager, Charles, Jr. "[http://www.answersingenesis.org/articles/arj/v1/n1/mars-testament-catastrophe Mars, a Testament to Catastrophe]." ''Answers Research Journal'' 1 (2008): 89–93. Accessed September 23, 2008.</ref>

== Mars in popular culture ==
Mars has figured prominently in [[science fiction]] in the Western world for more than a century.

=== The War of the Worlds ===
The first novel speculating on a civilization on Mars was ''The War of the Worlds'' by [[H. G. Wells]], in 1897. Wells' Martians had a military strength that human civilization could not match, but ultimately perished after contracting various [[infectious disease]]s caused by microbes native to Earth to which the Martians effectively had no defense.

In 1938, actor/director [[Orson Welles]] and his Mercury Theater produced a [[radio]] drama based on this novel. Welles updated the novel to his own period but otherwise remained faithful to the source material. The broadcast created such a panic in the [[United States]] that Welles was compelled to order a broadcast disclaimer in mid-show and, at the end of the show, personally assure his listeners that no such thing as an extraterrestrial invasion had taken place.<ref name=Hamilton/>

H. G. Wells' novel would inspire two [[motion picture]] projects and one [[television]] series.

=== Other speculations on civilizations ===
Author [[Edgar Rice Burroughs]] published several novels speculating on an elaborate civilization on Mars to which humans traveled, but which was not bent on invading the earth. Author [[C. S. Lewis]], in his novel ''Out of the Silent Planet'', envisioned Mars as the home of three races of non-fallen beings that were instructed to regard the earth as off-limits on account of man's [[fall of man|fallen nature]].

With the abandonment of the Lowell canal theory, science fiction authors and dramatists envisioned Mars as home to a human colony, such as the situation in the television series ''[[Terrahawks]]''. But at least one motion-picture producer saw Mars as a place that very ancient [[astronaut]]s had once visited. These astronauts, according to this scenario, left behind some advanced equipment that a human rebel was subsequently able to use to give Mars a breathable atmosphere and thus facilitate the Martian colony's liberation from the civilization of earth, which in the story had become venal and tyrannical.

=== Speculation on microbes ===
Authors [[John B. Olson]] and [[Randall S. Ingermanson]] have recently speculated (''[[Oxygen (novel)|Oxygen]]'' and ''[[The Fifth Man]]'') about the finding of microbes on Mars, and the implications that such a discovery would hold for the [[Christianity|Christian]] faith and the possible "back-contamination" of the earth when the crew that found the microbes returned to earth.

== Observation and exploration ==
Observation of Mars has been ongoing since the ancients noted its existence and its movements. The invention of the telescope provoked the first serious study of Mars as a celestial object, and not a prophetic sign. Yet not all of this observation led to proper inferences. Percival Lowell's canal theory would lead to more than half a century of vain speculation on extraterrestrial civilization before the first successful exploratory missions would return evidence forcing the abandonment of that theory.

Mars has been the subject of more attempts to explore it, and more failures, than any other planet. Of approximately 37 separate missions to Mars, only 13 have had any success. The planetary scientists of the [[Union of Soviet Socialist Republics]], so successful in exploring [[Venus]], experienced ten mission failures before achieving their first success, seven years after the [[United States]] achieved success with its [[Mariner 4]] mission. That Soviet mission, [[Mars 3]] in 1971, succeeded in placing a lander on Mars, but the lander's system transmitted for only 20 seconds before failing.

In 1975, [[Project Viking]] achieved the most notable success by placing two orbiters and two landers on Mars. Neither nation would attempt any further missions to Mars until 1988, when the Soviets lost one craft en route and lost contact with the other ([[Phobos 2]] seconds after its rendezvous with Mars's inner [[moon]] [[Phobos]]. Nor was the United States' program immune to failure; its ''Mars Observer'' vessel was lost prior to arrival after some propulsion systems failed.<ref name=faq/>

In 1996 the [[Mars Global Surveyor]] enjoyed the most success to date, returning more images than all previous missions combined. In that same year, the United States landed the first mobile explorer, or "rover," called the [[Mars Pathfinder]].

The United States would, unfortunately, lose the next two successive craft that it sent to Mars. But its [[Mars Odyssey]] would arrive intact in 2001 and send back the first high-resolution images. Two years later the [[European Space Agency]] would successfully place its [[Mars Express]] orbiter in the Martian system; sadly, its associated landing craft would crash-land. The Mars Express orbiter continues in orbit around Mars.<ref name=esa>"[http://www.esa.int/SPECIALS/Mars_Express/ Mars Express home page]." European Space Agency. Accessed May 27, 2008.</ref>

[[Image:Mcmurdopan_spirit_big.jpg|thumb|left|150px||360 degree panorama from mars rover ''Spirit''.]]
The most successful missions to date have been the Mars Excursion Rover missions. Two of these sophisticated mobile robots, named ''Spirit'' and ''Opportunity'', launched in 2003 and arrived safely on Mars about six months later, on opposite sides of the planet. They have been running for four years now, at least fifteen times longer than they were warranted to run. The Opportunity rover has been taking pictures of the Victoria Crater, and Spirit has been photographing the Esperanza formation which contains "vesicular" basalt (characterized by multiple cavities representing dissolved gas escaping from solution during a volcanic eruption).<ref name=David>David, Leonard. "[http://www.space.com/missionlaunches/061228_rovers_update.html Mars Rovers: On the Roll to New Targets]." ''Space.com'' December 28, 2006. Accessed May 27, 2008.</ref>

On May 26, 2008, NASA placed a polar lander on Mars for the first time: the [[Phoenix lander]]. As of June 28, 2008, the Phoenix lander is functioning well and has already discovered water ice where it landed. Contrary to prior understandings, the Phoenix lander has found an alkaline soil that might be suitable for growing Earth vegetables.

At least one non-governmental group, calling itself the Mars Society, has been actively studying technologies appropriate to send a crew of from four to six astronauts to Mars for a roughly two-year stay.<ref name=marssoc>[http://www.marssociety.org/portal The Mars Society] global and USA portal. Accessed May 27, 2008.</ref>

In 2012 a rover named "Curiosity" landed on Mars. It is the first Martian lander to use RTGs (Radioisotope thermoelectric generators) instead of solar panels.

==Satellites==
Mars has two moons: [[Phobos]] and [[Deimos]] (which respectively mean "Fear and "Panic" in [[Greek language|Greek]]). Russian scientists in the 1950s posited that Phobos might be hollow, but these claims were discredited in the late 1960s.

== References ==
{{reflist|2}}

== Related Links ==
* [http://mars.jpl.nasa.gov/missions/log/ NASA Historical Log: Missions to Mars]
* [http://www.space.com/mars/ Space.com] All About Mars
* [http://www.google.com/mars/ Google Mars], an interactive topographical map
* [http://starchild.gsfc.nasa.gov/docs/StarChild/solar_system_level2/mars.html Mars: the Red Planet] by Starchild, an educational service of NASA.
* [http://www.war-of-the-worlds.org/ War of the Worlds] commemorative site.
* [http://www.solarviews.com/eng/terms.htm Glossary]
* [http://www.answersingenesis.org/articles/arj/v1/n1/mars-testament-catastrophe Mars, a Testament to Catastrophe]
* [http://www.youtube.com/watch?v=BnOhFXamYOc Catastrophic Model of Martian Geology I] Video
* [http://www.youtube.com/watch?v=6HwZ22eYhAg Catastrophic Model of Martian Geology II]Video
*[http://genesismission.4t.com/Video/Mars1.html Catastrophic Model of Martian Geology] With Video

{{solarsystem}}
[[Category:Mars]]

Mars

2015-01-28T00:07:17Z

ScKinney: /* Water on Mars */

''For the [[Roman]] god of war, see [[Mars (god)]]''

{{Planet|image=Mars Viking.jpg
|caption=Mars photographed by [[Viking Orbiter]]s
|symbol=Mars symbol.svg
|discname=Known to ancients
|origname=Roman god of war
|order=4
|primary=Sun
|periapsis=206,620,000 km<ref name=marsfact>Williams, David R. "[http://nssdc.gsfc.nasa.gov/planetary/factsheet/marsfact.html Mars Fact Sheet]." National Space Science Data Center, [[National Aeronautics and Space Administration|NASA]], November 29, 2007. Accessed May 27, 2008.</ref>
|apoapsis=249,230,000 km<ref name=marsfact/>
|semimajor=227,920,000 km<ref name=marsfact/>
|bode=1.6 AU
|circumference=1,429,033,627 km
|eccentricity=0.0935<ref name=marsfact/>
|sidereal=686.980 da<ref name=marsfact/>
|synodic=779.94 da<ref name=marsfact/>
|orbitspeed=24.077 km/s
|inclination=1.850°<ref name=marsfact/>
|reference=the ecliptic
|siderealday=24.6229 h<ref name=marsfact/>
|solarday=24.6597 h<ref name=marsfact/>
|rotatespeed=465.11 m/s
|axialtilt=25.19°<ref name=marsfact/>
|mass=6.4185 * 1023 kg<ref name=marsfact/>
|density=3,933 kg/m³<ref name=marsfact/>
|surfacegrav=3.71 m/s²<ref name=marsfact/>
|escapespeed=5.03 km/s<ref name=marsfact/>
|meanradius=3389.5 km<ref name=marsfact/>
|equatorradius =3396.2 km<ref name=marsfact/>
|polarradius=3376.2 km<ref name=marsfact/>
|surfacearea=144,800,000 km²
|mintemp=140 K<ref name=Arnett>Arnett, Bill. "[http://www.nineplanets.org/mars.html Entry for Mars]." ''The <s>Nine</s> 8 Planets'', September 26, 2006. Accessed May 27, 2008.</ref>
|meantemp=218 K<ref name=Arnett/>
|maxtemp=300 K<ref name=Arnett/>
|moons=2
|composition=Rock
|color=Red
|albedo=0.15<ref name=marsfact/>
|pmdm=2.1 * 1018 N-m/T<ref name=Humphreys>Humphreys, D. R. "[http://www.creationresearch.org/crsq/articles/21/21_3/21_3.html The Creation of Planetary Magnetic Fields]." ''[[Creation Research Society Quarterly]]'' 21(3), December 1984. Accessed April 29, 2008.</ref>
|cmdm=1.51 * 1023 N-m/T<ref name=Humphreys/>
|mdt=535 a<ref name=Humphreys/>
|mhl=370.83 a<ref name=calc>Calculated</ref>
}}
'''Mars''' is the fourth planet from the [[Sun]], after [[Mercury]], [[Venus]], and [[Earth]]. It is called "The Red Planet" on account of the [[iron oxide]] that covers much of its suface.

== Ancient knowledge and naming ==
Mars has the [[Rome|Roman]] name of the classical god of war. This name in turn derives from the [[Greece|Greek]] name ''Ares'' for this god. (The traditional symbol of Mars is his shield and spear.) The ancient [[Egypt]]ians simply called Mars ''Her Descher'', or "the red one."<ref name=Hamilton>Hamilton, Calvin J. "[http://www.solarviews.com/eng/mars.htm Entry for Mars]." ''Views on the Solar System'', 2008. Accessed May 27, 2008.</ref> The [[Hindu]]s call Mars Mangala, one of the Navagraha.<ref name=ucar>"[http://www.windows.ucar.edu/tour/link=/mythology/mangala.html&edu=high Mangala]." ''Windows to the Universe'', University Corporation for Atmospheric Research, University of Michigan, September, 2000. Accessed May 27, 2008.</ref> The [[Maya]] people also tracked Mars regularly.

== Orbital characteristics ==
Mars is in a slightly elliptical orbit around the Sun and maintains an average distance slightly more than 1.5 AU. The synodic period of Mars is roughly 26 months. This fact makes transfer windows to Mars more common than those to slower-orbiting object, such as Jupiter and Saturn.

== Rotational characteristics ==
Mars' sidereal and solar days are only slightly longer than the days of earth. This fact has led long-term Mars mission planners to adopt a permanent system for keeping time "local" to Mars. The first mission to use this "Mars solar clock" was [[Viking 1]] in 1976.<ref name=Allison>Allison, Michael, and Schmunk, Robert. "[http://www.giss.nasa.gov/tools/mars24/help/notes.html Technical Notes on Mars Solar Time as Adopted by the Mars24 Sunclock]." Goddard Institute for Space Studies, [[National Aeronautics and Space Administration|NASA]], May 20, 2008. Accessed May 27, 2008.</ref>

== Physical characteristics ==
Mars is half the size of Earth and has about 11% of earth's mass. The large proportion of [[iron]] in Mars' clay-like topsoil gives Mars its distinctive color.

The weather on Mars is seasonal, on account of Mars's axial inclination. Yet because Mars's orbit is so eccentric, "summer" and "winter" on the northern and southern hemispheres can vary greatly. Temperatures vary from 140 K to 300 K, with an average temperature of 210 K. (The freezing point of [[water]] is 273.15 K.)

=== Atmosphere ===
Mars' atmosphere is quite thin and has an average pressure of 6.36 mb or 0.636% of that of earth. Its chief components are 95.32% [[carbon dioxide]], 2.7% [[nitrogen]], 1.6% [[argon]], 0.13% [[oxygen]], and 0.08% [[carbon monoxide]]. In addition it has trace amounts of [[water]] (210 ppm), [[nitrogen oxide]] (100 ppm), [[neon]] (2.5 ppm), hydrogen-deuterium oxide (HDO) (0.85 ppm), [[krypton]] (0.3 ppm), and [[xenon]] (0.08 ppm). Winds on Mars vary in speed from 2-7 m/s in summer to 5-10 m/s in fall, though the [[Project Viking]] landers have recorded winds varying from 17-30 m/s during dust storms that have swept past the landing sites.<ref name=marsfact/>

Recent warming trends on Mars, including an apparent partial melt of the polar ice caps, have led at least one scientist to question the widely circulating theories of [[global warming]] on earth. Specifically, Habibullo Abdussamatov, head of space research at St. Petersburg's Pulkovo Astronomical Observatory in Russia, asserts that the sun, and not any activity specific to the earth, must be responsible for any warming observed on either planet.<ref name=ngs>Ravilious, Kate. "[http://news.nationalgeographic.com/news/2007/02/070228-mars-warming.html Mars Melt Hints at Solar, Not Human, Cause for Warming, Scientist Says]." ''National Geographic News'', National Geographic Society, February 28, 2007. Accessed May 27, 2008.</ref>

=== Magnetosphere ===
Mars has a very weak magnetic field. Data from various missions has established an upper limit of 2.1 * 1018 N-m/T on the [[magnetic dipole moment]] of Mars. According to [[Russell Humphreys]]'s model of the creation of magnetic fields, Mars probably had a magnetic dipole moment ''at creation'' of 1.51 * 1023 N-m/T. Thus Mars's magnetic field has been decaying very rapidly. This tremendous decay, and the presence on [[Mercury]] of a magnetic field of significant strength, baffles [[astronomy|astronomers]] who have assumed that magnetic fields form on rapidly moving planets that have conductive and liquid cores that can act as dynamos. In fact, Humphreys asserts that the characteristic that determines which of the [[Terrestrial Planet|terrestrial planets]] will have a persistent magnetic field is the core radius, and that the cores of all four of these planets have similar conductivities. Mercury and Earth have larger cores than do Mars and Venus. The lengths of the sidereal days on those worlds do not matter.<ref name=Humphreys/>

=== Geology ===
[[Image:MarsTopoMap-PIA02031 modest.jpg|left|thumb|300px|Topographic map of Mars.]]
There is a dichotomy on the surface of Mars; the northern hemisphere consists of low-lying volcanic plains, with the southern hemisphere consists of ancient, heavily-cratered highland plains. Mars also has two volcanic regions: Tharsis and Elysium. Within the Tharsis region is the largest volcano in the solar system, [[Olympus Mons]]. Olympus Mons is approximately 500 km across and is about the same size as the state of Arizona. Its peak is 24 km above the surrounding plains and it is surrounded by a vertical scarp 6 km high. A large canyon system, Valles Marineris, is located along the Martian equator east of the Tharsis region. Valles Marineris is 2-6km deep and 200-600km wide and approximately 4,500 km long (approximately the distance from San Francisco to Boston). The eastern part of Valles Marineris appears to have a tectonic origin, but the western part is characterized by features such as teardrop islands and longitudinal grooves, indicating it may have been formed by catastrophic flooding in the past. Such flooding may be possible under current climate conditions. Run-off channels in the cratered highland indicate a thicker atmosphere or warmer climate in the past that would have allowed water to be stable on the surface.

Recent satellite imagery has shown that Mars has a 3 kilometre deep ice cap around its polar regions. The northern polar region is surrounded by [[dune]] fields. During the Martian winter, a layer of carbon dioxide condenses at the poles and sublimates in the summer, leaving the water-ice and dust polar caps exposed. The ratio of dust to water-ice contained in the polar caps remains unknown.
[[Image:F035a72_processed.jpg|thumb|100px|left|Cydonia Mensae, home of the alleged "face on Mars."]]
Persistent rumors tell of a "face on Mars," allegedly located in the Cydonia Mensae region at coordinates 40.9°N and 9.45°W. This alleged "face" is located in the midst of several pyramids and other mountains. Prevailing opinion at NASA is that the "face" is a [[pareidolia|trick of the eye]] due to the unusual lighting conditions.<ref name=faq>Williams, David R. "[http://nssdc.gsfc.nasa.gov/planetary/planetaryfaq.html#Mars Frequently Asked Questions - Planetary - Mars]." National Space Science Data Center, [[National Aeronautics and Space Administration|NASA]], January 2, 2008. Accessed May 27, 2008.</ref>

=== Water on Mars ===
[[Image:Weeping_100.jpg|thumb|120px|right|Multiple gullies in a south-facing wall in the Gorgonum Chaos region on Mars]]
Mars cannot have liquid water on its surface. The thin atmosphere does not permit this, even during high summer on Mars. Yet the [[Mars Global Surveyor]] mission in June 2000 took photographs of gully-like formations on several precipices and crater walls on Mars. These formations tend to occur between 30° and 70° north and south latitude. Mission analysts further suggest that these formations are relatively fresh and estimate that liquid water might be found less than 500 meters beneath the surface.<ref name=msss>"[http://www.msss.com/mars_images/moc/june2000/ MOC Images Suggest Recent Sources of Liquid Water on Mars]." Malin Space Science Systems, June 22, 2000. Accessed May 27, 2008.</ref>

More recently, NASA's latest mission, the [[Phoenix lander]], has discovered what appears to be water ice very near the surface near Mars' north pole. Furthermore, analysis of a cubic meter of soil at this site reveals that the soil is far more [[alkali]]ne than expected, and has tolerable levels of salt and low levels of [[calcium]]. Investigators have even suggested that the soil might support the growth of an Earth vegetable, like [[asparagus]],<ref name=courier>"[http://www.news.com.au/couriermail/story/0,23739,23932393-5013016,00.html Scientists find soil on Mars good enough to grow asparagus]." ''The Courier Mail'', June 28, 2008. Accessed June 30, 2008.</ref> if not for the fact that the atmosphere is too thin for water to be a liquid.

== Life on Mars ==
The possibility that [[extraterrestrial life]] exists, or has existed, on Mars has been the subject of persistent scientific speculation for decades. The earliest speculation concerned a possible civilization on Mars,<ref name=Hamilton/> this after Percival Lowell theorized that the straight lines that several astronomers had seen on Mars were in fact artificial constructs, and specifically canals.<ref name=canals>"[http://ssed.gsfc.nasa.gov/tharsis/canals.html The canals of Mars--historical note]." Goddard Space Flight Center, [[National Aeronautics and Space Administration|NASA]], n.d. Accessed May 27, 2008.</ref> Lovell popularized his theory as early as 1906, and for a long time the suspicion of a non-human civilization native to Mars would find repeated expression in novels and dramatic presentations. Only with the first successful explorations of Mars would the scientific community, and the public, abandon that theory.

Current speculation concerns the possible finding of [[microbe]]s. These would be [[extremophile]]s, or microbes that survive and even grow in environments lethal to other forms of life. Direct attempts to find such life began in 1976 with the [[Viking 1]] and [[Viking 2]] landers. To date no positive sign of life on Mars has been found. The Viking landers found evidence of unexplained chemical activity, but no clear evidence of microbes. Whether the Viking landers would have been able to detect extremophiles, a concept unknown to the Viking mission planners, is unclear.<ref name=Hamilton/>

The [[astrobiology|astrobiologists]] involved with [[Project Viking]] suspect that Mars might be an inherently inhospitable environment for life. Ultraviolet light from the sun shines unchecked on Mars, on account of Mars' thin atmosphere and weak magnetic field. The soil of Mars is also very dry, and the soil has a high proportion of oxidizing agents.<ref name=Hamilton/>

== Problem for uniformitarian theories ==
The most formidable current problem that Mars poses for uniformitarians today is that its magnetic field is weak and inconsequential, while a planet (Mercury) of little more than half its weight does have a significant magnetic field. According to current theory, planets derive their magnetic fields by dynamo action. This requires fast rotation and liquid cores. Mars and Earth have comparable sidereal days, but Earth's magnetic field is strong enough to protect Earth from the [[solar wind]], while that of Mars is not. Mercury has a far longer sidereal day than Mars has, and yet Mercury has a significant magnetic field while Mars has none.

== Young Mars Creation model. ==
[[Image:Meridiani Planum.jpg|thumb|150px|right|Meridiani Planum region of Mars.]]

Discoveries by the [[Mars Excursion Rover]] ''Opportunity'' have led to a Young Mars Creation model of Martian geology. These discoveries combine with data from the rest of Mars to indicate a massive Martian catastrophe.

Since ''Opportunity'' landed in the Meridiani Planum region of Mars it has sent back findings showing that the area was once underwater and that the water was very acidic. This high concentration of [[sulfuric acid]] militates against this being a habitable sea. The entire Meridiani Planum region has much evidence of catastrophic flooding, including a clear inlet channel to the southeast and a splash zone in the north.

Mars contains the largest of three major geologic features in the Solar System. The largest impact basin, the largest volcanoes and the largest canyon are all found on Mars and in a clear relationship to each other. This relationship provides the key to understanding Martian geology.

[[Image:Mars topography.jpg|thumb|150px|right|Mars' global topography, and the relationship between the Hellas impact basin and the Tharsis volcanoes.]]Mars’ largest impact basin is called Hellas. As shown in the topography map, on exactly the other side of Mars from Hellas is Mount Alba Patera, the largest volcano by surface area. This antipodal juxtaposition suggests that the Hellas impact caused the eruptions of Alba Patera and the volcanoes of the Tharsis plateau to the south and southwest. To the east is found the gigantic rift valley called Valles Marineris.

These relationships indicate a major geologic catastrophe on Mars resulting in massive volcanic activity. The dating of this event from craters places it at about the time of the [[Great Flood]] on [[Earth]]. This volcanic activity would have increased Mars’s atmospheric pressure to allow liquid water to flow on the surface and thus allow the flooding of the Meridiani Planum region.

This shows that, like Earth, Mars has evidence that it is only a few thousands of years old and not 4.6 billion years old.<ref name=creager>Creager, Charles, Jr. "[http://www.answersingenesis.org/articles/arj/v1/n1/mars-testament-catastrophe Mars, a Testament to Catastrophe]." ''Answers Research Journal'' 1 (2008): 89–93. Accessed September 23, 2008.</ref>

== Mars in popular culture ==
Mars has figured prominently in [[science fiction]] in the Western world for more than a century.

=== The War of the Worlds ===
The first novel speculating on a civilization on Mars was ''The War of the Worlds'' by [[H. G. Wells]], in 1897. Wells' Martians had a military strength that human civilization could not match, but ultimately perished after contracting various [[infectious disease]]s caused by microbes native to Earth to which the Martians effectively had no defense.

In 1938, actor/director [[Orson Welles]] and his Mercury Theater produced a [[radio]] drama based on this novel. Welles updated the novel to his own period but otherwise remained faithful to the source material. The broadcast created such a panic in the [[United States]] that Welles was compelled to order a broadcast disclaimer in mid-show and, at the end of the show, personally assure his listeners that no such thing as an extraterrestrial invasion had taken place.<ref name=Hamilton/>

H. G. Wells' novel would inspire two [[motion picture]] projects and one [[television]] series.

=== Other speculations on civilizations ===
Author [[Edgar Rice Burroughs]] published several novels speculating on an elaborate civilization on Mars to which humans traveled, but which was not bent on invading the earth. Author [[C. S. Lewis]], in his novel ''Out of the Silent Planet'', envisioned Mars as the home of three races of non-fallen beings that were instructed to regard the earth as off-limits on account of man's [[fall of man|fallen nature]].

With the abandonment of the Lowell canal theory, science fiction authors and dramatists envisioned Mars as home to a human colony, such as the situation in the television series ''[[Terrahawks]]''. But at least one motion-picture producer saw Mars as a place that very ancient [[astronaut]]s had once visited. These astronauts, according to this scenario, left behind some advanced equipment that a human rebel was subsequently able to use to give Mars a breathable atmosphere and thus facilitate the Martian colony's liberation from the civilization of earth, which in the story had become venal and tyrannical.

=== Speculation on microbes ===
Authors [[John B. Olson]] and [[Randall S. Ingermanson]] have recently speculated (''[[Oxygen (novel)|Oxygen]]'' and ''[[The Fifth Man]]'') about the finding of microbes on Mars, and the implications that such a discovery would hold for the [[Christianity|Christian]] faith and the possible "back-contamination" of the earth when the crew that found the microbes returned to earth.

== Observation and exploration ==
Observation of Mars has been ongoing since the ancients noted its existence and its movements. The invention of the telescope provoked the first serious study of Mars as a celestial object, and not a prophetic sign. Yet not all of this observation led to proper inferences. Percival Lowell's canal theory would lead to more than half a century of vain speculation on extraterrestrial civilization before the first successful exploratory missions would return evidence forcing the abandonment of that theory.

Mars has been the subject of more attempts to explore it, and more failures, than any other planet. Of approximately 37 separate missions to Mars, only 13 have had any success. The planetary scientists of the [[Union of Soviet Socialist Republics]], so successful in exploring [[Venus]], experienced ten mission failures before achieving their first success, seven years after the [[United States]] achieved success with its [[Mariner 4]] mission. That Soviet mission, [[Mars 3]] in 1971, succeeded in placing a lander on Mars, but the lander's system transmitted for only 20 seconds before failing.

In 1975, [[Project Viking]] achieved the most notable success by placing two orbiters and two landers on Mars. Neither nation would attempt any further missions to Mars until 1988, when the Soviets lost one craft en route and lost contact with the other ([[Phobos 2]] seconds after its rendezvous with Mars's inner [[moon]] [[Phobos]]. Nor was the United States' program immune to failure; its ''Mars Observer'' vessel was lost prior to arrival after some propulsion systems failed.<ref name=faq/>

In 1996 the [[Mars Global Surveyor]] enjoyed the most success to date, returning more images than all previous missions combined. In that same year, the United States landed the first mobile explorer, or "rover," called the [[Mars Pathfinder]].

The United States would, unfortunately, lose the next two successive craft that it sent to Mars. But its [[Mars Odyssey]] would arrive intact in 2001 and send back the first high-resolution images. Two years later the [[European Space Agency]] would successfully place its [[Mars Express]] orbiter in the Martian system; sadly, its associated landing craft would crash-land. The Mars Express orbiter continues in orbit around Mars.<ref name=esa>"[http://www.esa.int/SPECIALS/Mars_Express/ Mars Express home page]." European Space Agency. Accessed May 27, 2008.</ref>

[[Image:Mcmurdopan_spirit_big.jpg|thumb|left|150px||360 degree panorama from mars rover ''Spirit''.]]
The most successful missions to date have been the Mars Excursion Rover missions. Two of these sophisticated mobile robots, named ''Spirit'' and ''Opportunity'', launched in 2003 and arrived safely on Mars about six months later, on opposite sides of the planet. They have been running for four years now, at least fifteen times longer than they were warranted to run. The Opportunity rover has been taking pictures of the Victoria Crater, and Spirit has been photographing the Esperanza formation which contains "vesicular" basalt (characterized by multiple cavities representing dissolved gas escaping from solution during a volcanic eruption).<ref name=David>David, Leonard. "[http://www.space.com/missionlaunches/061228_rovers_update.html Mars Rovers: On the Roll to New Targets]." ''Space.com'' December 28, 2006. Accessed May 27, 2008.</ref>

On May 26, 2008, NASA placed a polar lander on Mars for the first time: the [[Phoenix lander]]. As of June 28, 2008, the Phoenix lander is functioning well and has already discovered water ice where it landed. Contrary to prior understandings, the Phoenix lander has found an alkaline soil that might be suitable for growing Earth vegetables.

At least one non-governmental group, calling itself the Mars Society, has been actively studying technologies appropriate to send a crew of from four to six astronauts to Mars for a roughly two-year stay.<ref name=marssoc>[http://www.marssociety.org/portal The Mars Society] global and USA portal. Accessed May 27, 2008.</ref>

In 2012 a rover called "Curiosity" landed on the Mars. The rover is controlled by the [[NASA]] on Earth and in 2013 it could even drill in the Mars.<ref>http://www.nasa.gov/mission_pages/msl/multimedia/pia16728.html</ref>

==Satellites==
Mars has two moons: [[Phobos]] and [[Deimos]] (which respectively mean "Fear and "Panic" in [[Greek language|Greek]]). Russian scientists in the 1950s posited that Phobos might be hollow, but these claims were discredited in the late 1960s.

== References ==
{{reflist|2}}

== Related Links ==
* [http://mars.jpl.nasa.gov/missions/log/ NASA Historical Log: Missions to Mars]
* [http://www.space.com/mars/ Space.com] All About Mars
* [http://www.google.com/mars/ Google Mars], an interactive topographical map
* [http://starchild.gsfc.nasa.gov/docs/StarChild/solar_system_level2/mars.html Mars: the Red Planet] by Starchild, an educational service of NASA.
* [http://www.war-of-the-worlds.org/ War of the Worlds] commemorative site.
* [http://www.solarviews.com/eng/terms.htm Glossary]
* [http://www.answersingenesis.org/articles/arj/v1/n1/mars-testament-catastrophe Mars, a Testament to Catastrophe]
* [http://www.youtube.com/watch?v=BnOhFXamYOc Catastrophic Model of Martian Geology I] Video
* [http://www.youtube.com/watch?v=6HwZ22eYhAg Catastrophic Model of Martian Geology II]Video
*[http://genesismission.4t.com/Video/Mars1.html Catastrophic Model of Martian Geology] With Video

{{solarsystem}}
[[Category:Mars]]

Mars

2015-01-28T00:01:12Z

ScKinney: /* Orbital characteristics */

''For the [[Roman]] god of war, see [[Mars (god)]]''

{{Planet|image=Mars Viking.jpg
|caption=Mars photographed by [[Viking Orbiter]]s
|symbol=Mars symbol.svg
|discname=Known to ancients
|origname=Roman god of war
|order=4
|primary=Sun
|periapsis=206,620,000 km<ref name=marsfact>Williams, David R. "[http://nssdc.gsfc.nasa.gov/planetary/factsheet/marsfact.html Mars Fact Sheet]." National Space Science Data Center, [[National Aeronautics and Space Administration|NASA]], November 29, 2007. Accessed May 27, 2008.</ref>
|apoapsis=249,230,000 km<ref name=marsfact/>
|semimajor=227,920,000 km<ref name=marsfact/>
|bode=1.6 AU
|circumference=1,429,033,627 km
|eccentricity=0.0935<ref name=marsfact/>
|sidereal=686.980 da<ref name=marsfact/>
|synodic=779.94 da<ref name=marsfact/>
|orbitspeed=24.077 km/s
|inclination=1.850°<ref name=marsfact/>
|reference=the ecliptic
|siderealday=24.6229 h<ref name=marsfact/>
|solarday=24.6597 h<ref name=marsfact/>
|rotatespeed=465.11 m/s
|axialtilt=25.19°<ref name=marsfact/>
|mass=6.4185 * 1023 kg<ref name=marsfact/>
|density=3,933 kg/m³<ref name=marsfact/>
|surfacegrav=3.71 m/s²<ref name=marsfact/>
|escapespeed=5.03 km/s<ref name=marsfact/>
|meanradius=3389.5 km<ref name=marsfact/>
|equatorradius =3396.2 km<ref name=marsfact/>
|polarradius=3376.2 km<ref name=marsfact/>
|surfacearea=144,800,000 km²
|mintemp=140 K<ref name=Arnett>Arnett, Bill. "[http://www.nineplanets.org/mars.html Entry for Mars]." ''The <s>Nine</s> 8 Planets'', September 26, 2006. Accessed May 27, 2008.</ref>
|meantemp=218 K<ref name=Arnett/>
|maxtemp=300 K<ref name=Arnett/>
|moons=2
|composition=Rock
|color=Red
|albedo=0.15<ref name=marsfact/>
|pmdm=2.1 * 1018 N-m/T<ref name=Humphreys>Humphreys, D. R. "[http://www.creationresearch.org/crsq/articles/21/21_3/21_3.html The Creation of Planetary Magnetic Fields]." ''[[Creation Research Society Quarterly]]'' 21(3), December 1984. Accessed April 29, 2008.</ref>
|cmdm=1.51 * 1023 N-m/T<ref name=Humphreys/>
|mdt=535 a<ref name=Humphreys/>
|mhl=370.83 a<ref name=calc>Calculated</ref>
}}
'''Mars''' is the fourth planet from the [[Sun]], after [[Mercury]], [[Venus]], and [[Earth]]. It is called "The Red Planet" on account of the [[iron oxide]] that covers much of its suface.

== Ancient knowledge and naming ==
Mars has the [[Rome|Roman]] name of the classical god of war. This name in turn derives from the [[Greece|Greek]] name ''Ares'' for this god. (The traditional symbol of Mars is his shield and spear.) The ancient [[Egypt]]ians simply called Mars ''Her Descher'', or "the red one."<ref name=Hamilton>Hamilton, Calvin J. "[http://www.solarviews.com/eng/mars.htm Entry for Mars]." ''Views on the Solar System'', 2008. Accessed May 27, 2008.</ref> The [[Hindu]]s call Mars Mangala, one of the Navagraha.<ref name=ucar>"[http://www.windows.ucar.edu/tour/link=/mythology/mangala.html&edu=high Mangala]." ''Windows to the Universe'', University Corporation for Atmospheric Research, University of Michigan, September, 2000. Accessed May 27, 2008.</ref> The [[Maya]] people also tracked Mars regularly.

== Orbital characteristics ==
Mars is in a slightly elliptical orbit around the Sun and maintains an average distance slightly more than 1.5 AU. The synodic period of Mars is roughly 26 months. This fact makes transfer windows to Mars more common than those to slower-orbiting object, such as Jupiter and Saturn.

== Rotational characteristics ==
Mars' sidereal and solar days are only slightly longer than the days of earth. This fact has led long-term Mars mission planners to adopt a permanent system for keeping time "local" to Mars. The first mission to use this "Mars solar clock" was [[Viking 1]] in 1976.<ref name=Allison>Allison, Michael, and Schmunk, Robert. "[http://www.giss.nasa.gov/tools/mars24/help/notes.html Technical Notes on Mars Solar Time as Adopted by the Mars24 Sunclock]." Goddard Institute for Space Studies, [[National Aeronautics and Space Administration|NASA]], May 20, 2008. Accessed May 27, 2008.</ref>

== Physical characteristics ==
Mars is half the size of Earth and has about 11% of earth's mass. The large proportion of [[iron]] in Mars' clay-like topsoil gives Mars its distinctive color.

The weather on Mars is seasonal, on account of Mars's axial inclination. Yet because Mars's orbit is so eccentric, "summer" and "winter" on the northern and southern hemispheres can vary greatly. Temperatures vary from 140 K to 300 K, with an average temperature of 210 K. (The freezing point of [[water]] is 273.15 K.)

=== Atmosphere ===
Mars' atmosphere is quite thin and has an average pressure of 6.36 mb or 0.636% of that of earth. Its chief components are 95.32% [[carbon dioxide]], 2.7% [[nitrogen]], 1.6% [[argon]], 0.13% [[oxygen]], and 0.08% [[carbon monoxide]]. In addition it has trace amounts of [[water]] (210 ppm), [[nitrogen oxide]] (100 ppm), [[neon]] (2.5 ppm), hydrogen-deuterium oxide (HDO) (0.85 ppm), [[krypton]] (0.3 ppm), and [[xenon]] (0.08 ppm). Winds on Mars vary in speed from 2-7 m/s in summer to 5-10 m/s in fall, though the [[Project Viking]] landers have recorded winds varying from 17-30 m/s during dust storms that have swept past the landing sites.<ref name=marsfact/>

Recent warming trends on Mars, including an apparent partial melt of the polar ice caps, have led at least one scientist to question the widely circulating theories of [[global warming]] on earth. Specifically, Habibullo Abdussamatov, head of space research at St. Petersburg's Pulkovo Astronomical Observatory in Russia, asserts that the sun, and not any activity specific to the earth, must be responsible for any warming observed on either planet.<ref name=ngs>Ravilious, Kate. "[http://news.nationalgeographic.com/news/2007/02/070228-mars-warming.html Mars Melt Hints at Solar, Not Human, Cause for Warming, Scientist Says]." ''National Geographic News'', National Geographic Society, February 28, 2007. Accessed May 27, 2008.</ref>

=== Magnetosphere ===
Mars has a very weak magnetic field. Data from various missions has established an upper limit of 2.1 * 1018 N-m/T on the [[magnetic dipole moment]] of Mars. According to [[Russell Humphreys]]'s model of the creation of magnetic fields, Mars probably had a magnetic dipole moment ''at creation'' of 1.51 * 1023 N-m/T. Thus Mars's magnetic field has been decaying very rapidly. This tremendous decay, and the presence on [[Mercury]] of a magnetic field of significant strength, baffles [[astronomy|astronomers]] who have assumed that magnetic fields form on rapidly moving planets that have conductive and liquid cores that can act as dynamos. In fact, Humphreys asserts that the characteristic that determines which of the [[Terrestrial Planet|terrestrial planets]] will have a persistent magnetic field is the core radius, and that the cores of all four of these planets have similar conductivities. Mercury and Earth have larger cores than do Mars and Venus. The lengths of the sidereal days on those worlds do not matter.<ref name=Humphreys/>

=== Geology ===
[[Image:MarsTopoMap-PIA02031 modest.jpg|left|thumb|300px|Topographic map of Mars.]]
There is a dichotomy on the surface of Mars; the northern hemisphere consists of low-lying volcanic plains, with the southern hemisphere consists of ancient, heavily-cratered highland plains. Mars also has two volcanic regions: Tharsis and Elysium. Within the Tharsis region is the largest volcano in the solar system, [[Olympus Mons]]. Olympus Mons is approximately 500 km across and is about the same size as the state of Arizona. Its peak is 24 km above the surrounding plains and it is surrounded by a vertical scarp 6 km high. A large canyon system, Valles Marineris, is located along the Martian equator east of the Tharsis region. Valles Marineris is 2-6km deep and 200-600km wide and approximately 4,500 km long (approximately the distance from San Francisco to Boston). The eastern part of Valles Marineris appears to have a tectonic origin, but the western part is characterized by features such as teardrop islands and longitudinal grooves, indicating it may have been formed by catastrophic flooding in the past. Such flooding may be possible under current climate conditions. Run-off channels in the cratered highland indicate a thicker atmosphere or warmer climate in the past that would have allowed water to be stable on the surface.

Recent satellite imagery has shown that Mars has a 3 kilometre deep ice cap around its polar regions. The northern polar region is surrounded by [[dune]] fields. During the Martian winter, a layer of carbon dioxide condenses at the poles and sublimates in the summer, leaving the water-ice and dust polar caps exposed. The ratio of dust to water-ice contained in the polar caps remains unknown.
[[Image:F035a72_processed.jpg|thumb|100px|left|Cydonia Mensae, home of the alleged "face on Mars."]]
Persistent rumors tell of a "face on Mars," allegedly located in the Cydonia Mensae region at coordinates 40.9°N and 9.45°W. This alleged "face" is located in the midst of several pyramids and other mountains. Prevailing opinion at NASA is that the "face" is a [[pareidolia|trick of the eye]] due to the unusual lighting conditions.<ref name=faq>Williams, David R. "[http://nssdc.gsfc.nasa.gov/planetary/planetaryfaq.html#Mars Frequently Asked Questions - Planetary - Mars]." National Space Science Data Center, [[National Aeronautics and Space Administration|NASA]], January 2, 2008. Accessed May 27, 2008.</ref>

=== Water on Mars ===
[[Image:Weeping_100.jpg|thumb|120px|right|Multiple gullies in a south-facing wall in the Gorgonum Chaos region on Mars]]
Mars cannot have liquid water on its surface. The thin atmosphere does not permit this, even during high summer on Mars. Yet the [[Mars Global Surveyor]] mission in June 2000 took photographs of gully-like formations on several precipices and crater walls on Mars. These formations tend to occur between 30° and 70° north and south latitude. Mission analysts further suggest that these formations are relatively fresh and estimate that liquid water might be found less than 500 meters beneath the surface.<ref name=msss>"[http://www.msss.com/mars_images/moc/june2000/ MOC Images Suggest Recent Sources of Liquid Water on Mars]." Malin Space Science Systems, June 22, 2000. Accessed May 27, 2008.</ref>

More recently, NASA's latest mission, the [[Phoenix lander]], has discovered what appears to be water ice very near the surface near Mars' north pole. Furthermore, analysis of a cubic meter of soil at this site reveals that the soil is far more [[alkali]]ne than expected, and has tolerable levels of salt and low levels of [[calcium]]. Investigators have even suggested that the soil might support the growth of an Earth vegetable, like [[asparagus]].<ref name=courier>"[http://www.news.com.au/couriermail/story/0,23739,23932393-5013016,00.html Scientists find soil on Mars good enough to grow asparagus]." ''The Courier Mail'', June 28, 2008. Accessed June 30, 2008.</ref>

== Life on Mars ==
The possibility that [[extraterrestrial life]] exists, or has existed, on Mars has been the subject of persistent scientific speculation for decades. The earliest speculation concerned a possible civilization on Mars,<ref name=Hamilton/> this after Percival Lowell theorized that the straight lines that several astronomers had seen on Mars were in fact artificial constructs, and specifically canals.<ref name=canals>"[http://ssed.gsfc.nasa.gov/tharsis/canals.html The canals of Mars--historical note]." Goddard Space Flight Center, [[National Aeronautics and Space Administration|NASA]], n.d. Accessed May 27, 2008.</ref> Lovell popularized his theory as early as 1906, and for a long time the suspicion of a non-human civilization native to Mars would find repeated expression in novels and dramatic presentations. Only with the first successful explorations of Mars would the scientific community, and the public, abandon that theory.

Current speculation concerns the possible finding of [[microbe]]s. These would be [[extremophile]]s, or microbes that survive and even grow in environments lethal to other forms of life. Direct attempts to find such life began in 1976 with the [[Viking 1]] and [[Viking 2]] landers. To date no positive sign of life on Mars has been found. The Viking landers found evidence of unexplained chemical activity, but no clear evidence of microbes. Whether the Viking landers would have been able to detect extremophiles, a concept unknown to the Viking mission planners, is unclear.<ref name=Hamilton/>

The [[astrobiology|astrobiologists]] involved with [[Project Viking]] suspect that Mars might be an inherently inhospitable environment for life. Ultraviolet light from the sun shines unchecked on Mars, on account of Mars' thin atmosphere and weak magnetic field. The soil of Mars is also very dry, and the soil has a high proportion of oxidizing agents.<ref name=Hamilton/>

== Problem for uniformitarian theories ==
The most formidable current problem that Mars poses for uniformitarians today is that its magnetic field is weak and inconsequential, while a planet (Mercury) of little more than half its weight does have a significant magnetic field. According to current theory, planets derive their magnetic fields by dynamo action. This requires fast rotation and liquid cores. Mars and Earth have comparable sidereal days, but Earth's magnetic field is strong enough to protect Earth from the [[solar wind]], while that of Mars is not. Mercury has a far longer sidereal day than Mars has, and yet Mercury has a significant magnetic field while Mars has none.

== Young Mars Creation model. ==
[[Image:Meridiani Planum.jpg|thumb|150px|right|Meridiani Planum region of Mars.]]

Discoveries by the [[Mars Excursion Rover]] ''Opportunity'' have led to a Young Mars Creation model of Martian geology. These discoveries combine with data from the rest of Mars to indicate a massive Martian catastrophe.

Since ''Opportunity'' landed in the Meridiani Planum region of Mars it has sent back findings showing that the area was once underwater and that the water was very acidic. This high concentration of [[sulfuric acid]] militates against this being a habitable sea. The entire Meridiani Planum region has much evidence of catastrophic flooding, including a clear inlet channel to the southeast and a splash zone in the north.

Mars contains the largest of three major geologic features in the Solar System. The largest impact basin, the largest volcanoes and the largest canyon are all found on Mars and in a clear relationship to each other. This relationship provides the key to understanding Martian geology.

[[Image:Mars topography.jpg|thumb|150px|right|Mars' global topography, and the relationship between the Hellas impact basin and the Tharsis volcanoes.]]Mars’ largest impact basin is called Hellas. As shown in the topography map, on exactly the other side of Mars from Hellas is Mount Alba Patera, the largest volcano by surface area. This antipodal juxtaposition suggests that the Hellas impact caused the eruptions of Alba Patera and the volcanoes of the Tharsis plateau to the south and southwest. To the east is found the gigantic rift valley called Valles Marineris.

These relationships indicate a major geologic catastrophe on Mars resulting in massive volcanic activity. The dating of this event from craters places it at about the time of the [[Great Flood]] on [[Earth]]. This volcanic activity would have increased Mars’s atmospheric pressure to allow liquid water to flow on the surface and thus allow the flooding of the Meridiani Planum region.

This shows that, like Earth, Mars has evidence that it is only a few thousands of years old and not 4.6 billion years old.<ref name=creager>Creager, Charles, Jr. "[http://www.answersingenesis.org/articles/arj/v1/n1/mars-testament-catastrophe Mars, a Testament to Catastrophe]." ''Answers Research Journal'' 1 (2008): 89–93. Accessed September 23, 2008.</ref>

== Mars in popular culture ==
Mars has figured prominently in [[science fiction]] in the Western world for more than a century.

=== The War of the Worlds ===
The first novel speculating on a civilization on Mars was ''The War of the Worlds'' by [[H. G. Wells]], in 1897. Wells' Martians had a military strength that human civilization could not match, but ultimately perished after contracting various [[infectious disease]]s caused by microbes native to Earth to which the Martians effectively had no defense.

In 1938, actor/director [[Orson Welles]] and his Mercury Theater produced a [[radio]] drama based on this novel. Welles updated the novel to his own period but otherwise remained faithful to the source material. The broadcast created such a panic in the [[United States]] that Welles was compelled to order a broadcast disclaimer in mid-show and, at the end of the show, personally assure his listeners that no such thing as an extraterrestrial invasion had taken place.<ref name=Hamilton/>

H. G. Wells' novel would inspire two [[motion picture]] projects and one [[television]] series.

=== Other speculations on civilizations ===
Author [[Edgar Rice Burroughs]] published several novels speculating on an elaborate civilization on Mars to which humans traveled, but which was not bent on invading the earth. Author [[C. S. Lewis]], in his novel ''Out of the Silent Planet'', envisioned Mars as the home of three races of non-fallen beings that were instructed to regard the earth as off-limits on account of man's [[fall of man|fallen nature]].

With the abandonment of the Lowell canal theory, science fiction authors and dramatists envisioned Mars as home to a human colony, such as the situation in the television series ''[[Terrahawks]]''. But at least one motion-picture producer saw Mars as a place that very ancient [[astronaut]]s had once visited. These astronauts, according to this scenario, left behind some advanced equipment that a human rebel was subsequently able to use to give Mars a breathable atmosphere and thus facilitate the Martian colony's liberation from the civilization of earth, which in the story had become venal and tyrannical.

=== Speculation on microbes ===
Authors [[John B. Olson]] and [[Randall S. Ingermanson]] have recently speculated (''[[Oxygen (novel)|Oxygen]]'' and ''[[The Fifth Man]]'') about the finding of microbes on Mars, and the implications that such a discovery would hold for the [[Christianity|Christian]] faith and the possible "back-contamination" of the earth when the crew that found the microbes returned to earth.

== Observation and exploration ==
Observation of Mars has been ongoing since the ancients noted its existence and its movements. The invention of the telescope provoked the first serious study of Mars as a celestial object, and not a prophetic sign. Yet not all of this observation led to proper inferences. Percival Lowell's canal theory would lead to more than half a century of vain speculation on extraterrestrial civilization before the first successful exploratory missions would return evidence forcing the abandonment of that theory.

Mars has been the subject of more attempts to explore it, and more failures, than any other planet. Of approximately 37 separate missions to Mars, only 13 have had any success. The planetary scientists of the [[Union of Soviet Socialist Republics]], so successful in exploring [[Venus]], experienced ten mission failures before achieving their first success, seven years after the [[United States]] achieved success with its [[Mariner 4]] mission. That Soviet mission, [[Mars 3]] in 1971, succeeded in placing a lander on Mars, but the lander's system transmitted for only 20 seconds before failing.

In 1975, [[Project Viking]] achieved the most notable success by placing two orbiters and two landers on Mars. Neither nation would attempt any further missions to Mars until 1988, when the Soviets lost one craft en route and lost contact with the other ([[Phobos 2]] seconds after its rendezvous with Mars's inner [[moon]] [[Phobos]]. Nor was the United States' program immune to failure; its ''Mars Observer'' vessel was lost prior to arrival after some propulsion systems failed.<ref name=faq/>

In 1996 the [[Mars Global Surveyor]] enjoyed the most success to date, returning more images than all previous missions combined. In that same year, the United States landed the first mobile explorer, or "rover," called the [[Mars Pathfinder]].

The United States would, unfortunately, lose the next two successive craft that it sent to Mars. But its [[Mars Odyssey]] would arrive intact in 2001 and send back the first high-resolution images. Two years later the [[European Space Agency]] would successfully place its [[Mars Express]] orbiter in the Martian system; sadly, its associated landing craft would crash-land. The Mars Express orbiter continues in orbit around Mars.<ref name=esa>"[http://www.esa.int/SPECIALS/Mars_Express/ Mars Express home page]." European Space Agency. Accessed May 27, 2008.</ref>

[[Image:Mcmurdopan_spirit_big.jpg|thumb|left|150px||360 degree panorama from mars rover ''Spirit''.]]
The most successful missions to date have been the Mars Excursion Rover missions. Two of these sophisticated mobile robots, named ''Spirit'' and ''Opportunity'', launched in 2003 and arrived safely on Mars about six months later, on opposite sides of the planet. They have been running for four years now, at least fifteen times longer than they were warranted to run. The Opportunity rover has been taking pictures of the Victoria Crater, and Spirit has been photographing the Esperanza formation which contains "vesicular" basalt (characterized by multiple cavities representing dissolved gas escaping from solution during a volcanic eruption).<ref name=David>David, Leonard. "[http://www.space.com/missionlaunches/061228_rovers_update.html Mars Rovers: On the Roll to New Targets]." ''Space.com'' December 28, 2006. Accessed May 27, 2008.</ref>

On May 26, 2008, NASA placed a polar lander on Mars for the first time: the [[Phoenix lander]]. As of June 28, 2008, the Phoenix lander is functioning well and has already discovered water ice where it landed. Contrary to prior understandings, the Phoenix lander has found an alkaline soil that might be suitable for growing Earth vegetables.

At least one non-governmental group, calling itself the Mars Society, has been actively studying technologies appropriate to send a crew of from four to six astronauts to Mars for a roughly two-year stay.<ref name=marssoc>[http://www.marssociety.org/portal The Mars Society] global and USA portal. Accessed May 27, 2008.</ref>

In 2012 a rover called "Curiosity" landed on the Mars. The rover is controlled by the [[NASA]] on Earth and in 2013 it could even drill in the Mars.<ref>http://www.nasa.gov/mission_pages/msl/multimedia/pia16728.html</ref>

==Satellites==
Mars has two moons: [[Phobos]] and [[Deimos]] (which respectively mean "Fear and "Panic" in [[Greek language|Greek]]). Russian scientists in the 1950s posited that Phobos might be hollow, but these claims were discredited in the late 1960s.

== References ==
{{reflist|2}}

== Related Links ==
* [http://mars.jpl.nasa.gov/missions/log/ NASA Historical Log: Missions to Mars]
* [http://www.space.com/mars/ Space.com] All About Mars
* [http://www.google.com/mars/ Google Mars], an interactive topographical map
* [http://starchild.gsfc.nasa.gov/docs/StarChild/solar_system_level2/mars.html Mars: the Red Planet] by Starchild, an educational service of NASA.
* [http://www.war-of-the-worlds.org/ War of the Worlds] commemorative site.
* [http://www.solarviews.com/eng/terms.htm Glossary]
* [http://www.answersingenesis.org/articles/arj/v1/n1/mars-testament-catastrophe Mars, a Testament to Catastrophe]
* [http://www.youtube.com/watch?v=BnOhFXamYOc Catastrophic Model of Martian Geology I] Video
* [http://www.youtube.com/watch?v=6HwZ22eYhAg Catastrophic Model of Martian Geology II]Video
*[http://genesismission.4t.com/Video/Mars1.html Catastrophic Model of Martian Geology] With Video

{{solarsystem}}
[[Category:Mars]]