Extraterrestrial life is life, whether demonstrated, hypothesized, or merely imagined, that did not obviously originate on the Earth. It has been a staple of science fiction since the Edwardian era, and has more recently become the subject of scientific and even theological debates.
The term life is here used in its usual manner to denote living things, regardless of complexity or sentience. However, in science fiction especially, extraterrestrial life may take unconventional forms, such as non-carbon-based life forms or even disembodied intelligence.
The term race here means a species of sentient individuals (not an ethnographic subdivision of a single species); for example, humans all belong to only one race, the human race.
- 1 Extraterrestrial life as a scientific hypothesis
- 2 Extraterrestrial Life in Science Fiction
- 3 Religious Views on Extraterrestrial Life
- 4 Public speculation on ET's and UFO's
- 5 See also
- 6 References
- 7 See also
Extraterrestrial life as a scientific hypothesis
Vigorous scientific research on the subject is fairly limited, and has focused on both the "micro" and "macro" aspects of the problem:
- The genesis, nature, survival, and movement of primitive life forms, including the hazard that spaceborne microbes might pose to astronauts or to the Earth itself.
- The possibility of prior or future detection, contact, trade, or war with an extraterrestrial civilization.
Microbes and other primitive forms
Extraterrestrial microbes have been and remain the subject of much serious scientific speculation. Such speculation has centered on three questions:
- Could a microbe of extraterrestrial origin somehow come to Earth and cause a killer pandemic?
- Did life on Earth begin with the "seeding" of the earth from outside? This theory, called panspermia, alleges that either (a) the Earth acquired the seeds of life by passing through the tail of a comet, or (b) an extraterrestrial civilization sent the seeds of life deliberately for one reason or another. Extraterrestrial microbes would be involved in either case.
- Might a human crew or human-directed robotic explorer find extraterrestrial microbes on another planet?
With the continued development and perfection of telescopes, astronomers and rocket scientists have openly and often feverishly speculated about whether the other planets in the Solar System might harbor forms of life that originated on those planets. This speculation has also extended to Titan, the largest satellite of the planet Saturn.
The major considerations driving such speculation are the requirements of life, and the difficulty with the theory of abiogenesis as a workable origin of life on Earth. Most scientists engaged in such speculation seem to agree that life requires at least two things in order to self-generate in any environment:
Currently the most exciting subject for speculation concerning extraterrestrial life is the planet Mars. Its atmosphere is quite thin, and this would militate against the presence of life or, more to the point, the presence of standing or flowing water. But photographs taken from orbit and from the surface of Mars reveal erosion channels that strongly suggest that water once flowed on Mars. Indeed, the first graphic above shows changes in a gully in two views of it, taken four years apart—as if liquid water had opened another erosion channel in the meantime. (The operators of the Mars Global Surveyor insist that such pictures might still contain artifacts that make them unsuitable for scientific research, and hence disclaim any definite conclusion that anyone might be tempted to draw from them.) The second graphic shows a meteorite, found in Antarctica in 1984, containing microscopic cavities that once might have held microbes and that, until recently, was believed to have fallen to Earth from Mars.
If one could show that abiogenesis occurred on Mars, then that process was far more likely to have occurred on Earth than it would be absent such a showing or finding. Yet apart from the reliability of such evidence is this one inherent weakness for this argument: it assumes that life found on Mars originated on Mars. The hydroplate theory of the Great Flood suggests that large quantities of water, including muddy slurries, were ejected into space during the initial fissure of the original earth's crust, and that these ejecta persist today as comets, asteroids, and meteoroids. If such ejected water and mud fell to Mars from above, then they might have held microbes—and therefore any microbes found on Mars are far more likely to have come from Earth during the Noachic Flood than to have originated on Mars.
Space scientists have searched for extraterrestrial microbes for years. To date, no definitive proof of such microbes has been found. The Antarctic meteorite mentioned above, and the alleged bacterial fossils on it, fueled speculation for months, until other scientists finally determined that the microbes involved probably were earthly contaminants.
Nevertheless, the finding of extraterrestrial microbes on Mars is one of the fondest expressed hopes of NASA planetary scientists and of other scientists and advocacy groups hoping to persuade the United States government, or perhaps the United Nations, to fund crewed expeditions to Mars. Furthermore, no sane space mission planner could in good conscience ignore the potential hazard of the transport of a microbe to Earth and the release of that microbe into Earth's biosphere. Happily, measures for containing such a microbe, perhaps derived from those measures taken during Project Apollo, would contribute a relatively insignificant amount to the total budget of a program of crewed missions to Mars or to any other celestial body.
Francis Crick and Leslie Orgel, in 1973, openly speculated on a form of exogenesis called directed panspermia, in which such an extraterrestrial nation-state fired a brace of missiles, each laden with bacteria and/or blue-green algae, in all directions. One such missile crashed on Earth, and we are its by-product, as it were, their theory states.
Candidates for extraterrestrial life in our Solar System according to evolutionary pseudoscience
Besides Earth there are two moons and one planet that scientists consider possibly habitable to some form of life.
- Mars, as mentioned above, is the most popular candidate. Ice is known to exist at the poles. Some liquid water might exist on Mars because temperatures occasionally rise above freezing.
- The Jovian moon Europa is covered with a thick sheet of ice. Scientists speculate that a liquid ocean may exist under the crust and that may harbor life.
- Titan, a moon of Saturn, has approximately the same percentage of nitrogen in its atmosphere as in Earth's. Titan also has oceans and thick clouds. Scientists have determined that the oceans are liquid methane, not water, and that the low temperatures of -178° Celsius make life, at least as we know it, highly improbable.
Do one or more extraterrestrial civilizations exist? Until recently, speculation about extraterrestrial races was confined either to science fiction or to innumerable anecdotal reports of "unidentified flying objects." These latter reports were once the subject of an investigation, known as Project Blue Book, by the United States Air Force. But years after Blue Book wound down, a large cadre of scientists began to entertain seriously the notion that extraterrestrial civilizations might exist.
SETI (Search for Extraterrestrial Intelligence) is the name given to several government and privately-funded projects that over the years have searched for evidence of extraterrestrial civilizations. This is done by listening via radio telescope on a defined frequency band for any transmission having any semblance of order. The frequency band is one that, they believe, is the likeliest region in the electromagnetic spectrum for anyone to be sending a signal intended to cross interstellar, or even intergalactic, space.
No definitive evidence exists for any form of extraterrestrial civilization. While the Project Blue Book investigators found a number of cases that they had to classify as "unknown," they were able to classify the bulk of the anecdotes as outright hoaxes, misinterpretations of common weather features, or misinterpretations of sightings of ordinary aircraft. Neither has any astronomer or astronaut reported a definite sighting of a vessel that could have launched any of the craft that witnesses report having encountered. And the SETI projects, despite years of searching for a signal (at one point recruiting civilians to participate in a "distributed computing" project to process the noise they have received from their radiotelescopes), have never isolated anything like a definite signal.
In 1961, astronomer Frank Drake developed a method for estimating of the number of extraterrestrial civilizations in the galaxy. The Drake Equation simply begins with the number of stars, then multiplies that number by a series of probabilities (probability that a star has planets, that a planet can support life, etc.) to obtain the quantity desired (number of populated planets, number of civilizations whose existence is detectable, etc.).
In principle, the Drake Equation can provide an upper and lower bound for the number of extraterrestrial civilizations by setting upper and lower bounds for each probability factor, which can then be improved upon as better information becomes available. Because the number of stars is so huge, even the lower bound is often calculated to be a respectable number. However, a serious problem is that some of the probabilities are completely unknown, or even unknowable. For example, the probability of life emerging on a planet is a meaningless concept if life is created directly by God and not by some naturalistic process. If any of the probabilities appearing in the equation is zero, then the number of extraterrestrial civilizations of course goes to zero.
Extraterrestrial Life in Science Fiction
Extraterrestrial life, from nation-states to microbes, has been a staple of science fiction since the early days of the genre. Novelist H. G. Wells speculated on what sort of inventions might carry men into outer space, and what they might discover there. In The First Men in the Moon, he describes a fictional extraterrestrial civilization on the moon, populated by man-sized insects. Wells also wrote about a Martian nation-state that launched an invasion of Earth (The War of the Worlds), only to fail when the invaders fell terminally ill from earthly microbes against which their immune systems had no defense. Edgar Rice Burroughs indulged in far richer speculation on an entire civilization on Mars, and on semi-regular commerce between his Martians and a select few visitors from Earth.
The middle twentieth century introduced other now-familiar themes, often through the media of comic books, novels, low-budget films, and television: humans caught up in events on other inhabited worlds, spacefaring starship crews, and extraterrestrial "prophets" appearing on earth with either good intentions or bad. By the late twentieth century, big-budget films repeated these themes and introduced new ones, sometimes (as in Star Wars) bypassing Earth altogether in favor of mythlike tales of ancient civilizations. The alleged crash of an extraterrestrial scout craft near Roswell, New Mexico, United States was the subject of another film.
The Star Trek television franchise created by Gene Roddenberry, with its myriad of extraterrestrial and even trans-galactic empires, is well known. Also in the 1960s, producer Quinn Martin created the series The Invaders that centered on one man's attempt to warn his government that the Earth had been infiltrated with extraterrestrial spies. More recently, Kenneth Johnston created V, a series in which a spaceborne force whose commanding admiral at first puts on a friendly appearance (similar to that of Matthew Perry, the American commodore who first visited Japan) but then subverts human governmental and media institutions in order to further the aliens' true purpose, which is to steal earth's water and carry away earth's population for food.
Nor have science fiction writers ignored speculation about the finding of extraterrestrial microbes. Usually they have portrayed such microbes as capable of producing deadly extinction-level pandemics. (See, for example, The Andromeda Strain by Michael Crichton.) John B. Olson and Randall S. Ingermanson, however, speculated that the first crew to fly to Mars might discover incontrovertible evidence of microbial life—including a culturable microbe. This would engender excitement in the hearts of their launch authorities, but would also inspire such fear in the mind of a NASA engineer that she would actually attempt to strand or murder the crew to stop them from back-contaminating the earth with their culture.
Religious Views on Extraterrestrial Life
The question of whether the existence of an extraterrestrial race is compatible with the Bible is in sharp dispute. The dispute is probably of modern origin - the Catholic Church never issued any formal pronouncement on the question of alien life, and most Protestant confessions are silent on the matter. Those insisting that the Bible is entirely compatible with extraterrestrial races hold that the Bible contains no verse that says directly that man is the only sentient race in the universe.
John 10:16Compatibility advocates quote this verse:
I have other sheep, which are not of this fold; I must bring them also, and they will hear My voice; and they will become one flock with one shepherd. John 10:16 (NASB)
Critics of this position point out that that verse probably referred to the distinction between Jew and Gentile, and reject the proposition that "other sheep" might include extraterrestrial races.
Uniqueness of the Atonement
Opponents hold that the presence of such a race would give the lie to the claim of Jesus Christ that He came to take away the sin of the world, and that He died once and only once to bring this about. They contend that since Jesus is referred to singly (as he was an individual person), this rules out the possibility of an alien counterpart to Jesus, and that an alien counterpart to Jesus is a necessary precondition for an alien nation to exist.—and that Kingdom is also not of this universe, or "cosmos".
Defenders of the compatibility position might insist that neither of the two verses named above speaks directly to the uniqueness claim. But the original Hebrew and Greek texts use definite article adjectives and references to a specific person named Adam (and another, named Jesus), with no hint that either Adam or Jesus had any counterpart elsewhere in the cosmos. These things militate in favor of uniqueness almost as well as any direct negation of plurality might. Again, compatibility defenders might cite a lack of evidence that any hypothetical alien race would require counterparts to Jesus or Adam. But Christian critics reply that if the Bible is real at all, then life does not arise out of non-life. Therefore, every race would have its Adam—and if any given Adam did not fall into sin, then his race would be under strict Divine orders to avoid contact with humans until the "hour of temptation" (see above) came to pass.
The speculation concerning Jesus dying multiple deaths on other worlds has occasionally found poetic expression. See, for example, The Innumerable Christ by Hugh McDiarmid.
Extent of the Creation
The presence of extraterrestrial microbes on one or more of the other planets in the Solar System (most likely Mars) does cause some fear in Christian quarters. But not all Christians harbor such fear, and even young Earth creationists are quite confident that they could explain such a finding. For example, if the Hydroplate Theory is correct and a slurry of mud from the Great Flood traveled to Mars and poured itself out upon it, then such a slurry would almost certainly contain microbes. That some of these might be extremophiles, and thus capable of long-term survival even in such a harsh environment as that of Mars, is entirely possible and would allow complete harmony between the finding of microbes in such locations and the Biblical account of Earth's prehistory.
Outside of the Christian faith, other religions, as well as movements exhibiting characteristics common to pagan religions, have adopted or expressed tenets dealing with extraterrestrial life:
- Church of Scientology founder L. Ron Hubbard has lectured on and written accounts of complex extraterrestrial civilizations and alien interventions in earthly events.
- The Raelians believe that their minds are the once-disembodied souls of extraterrestrial persons (and therefore believe that their minds are extraterrestrial in origin though their bodies are not).
- The Hale-Bopp movement, whose members committed mass suicide in the season of the close passage near the Earth of Comet Hale-Bopp, believed they would be taken away by an alien craft concealed in the comet's tail.
- The UFO movement, a loose alliance of organizations often having the initials "UFO" (for Unidentified Flying Object) in their names, viz., "Mutual UFO Network", "Center for UFO Studies," "Fund for UFO Research", express various beliefs concerning the extrterrestrial nature of unidentified flying objects.
- The Nation of Islam, especially when it came under the leadership of Louis Farrakhan, expressed a belief that the original founder of the Nation of Islam lives today in an extraterrestrial spacecraft called the "Mother Wheel," and that Farrakhan himself has been taken on board that vessel for consultations with this person.
For a more detailed treatment, see Exotheology.
Many Christians examine the possibility of extraterrestrial life from within a Christian perspective. Many believe that if aliens exist they would necessarily be free from Original Sin as they are not descended from the Earthly Adam and Eve. Proponents of this view include the Vatican and C. S. Lewis who expanded upon the idea in his book Out of the Silent Planet. In the book a human explores Mars which, due to its isolation from Earth, is free from sin.
Public speculation on ET's and UFO's
Public discussion of the subject is mostly confined to the margins, but several scientists and celebrities have expressed opinions, as have a few politicians. Former President of the United States Jimmy Carter has openly speculated on the existence of extraterrestrial nation-states. More recently, US Representative and Presidential candidate Dennis Kucinich (D-OH) was asked in a primary debate whether he had, as earlier alleged, seen a UFO—and answered in the affirmative. Even more recently, Project Apollo Astronaut Edgar Mitchell, who flew as Lunar Module Pilot for Apollo 14, declared that NASA has known for sixty years (as of July 24, 2008) that extraterrestrial scouts have contacted various governments of Earth, yet no government has ever dared admit this. NASA does not stand by Astronaut Mitchell's statements.
Explanations given for UFO sightings and belief
Lynn Cato, senior bibliographer for the library of Congress, compiled a 1600-entry UFO bibliography for the United States Air Force Office of Scientific Research. After a two-year investigation, in which she reviewed thousands of documents, Catoe stated:
|“||A large part of the available UFO literature...deals with subjects like mental telepathy, automatic writing and invisible entities...poltergeist manifestations and 'possession'....Many of the UFO reports now being published in the popular press recount alleged incidents that are strikingly similar to demonic possession and psychic phenomenon which have long been known to theologians and parapsychologists.||”|
|“||The manifestations and occurrences described in this imposing literature are similar if not entirely identical to the UFO phenomenon itself.||”|
Astronomer Dr. Hugh Ross states that ninety-nine percent of what people have told him were UFOs, experienced astronomers can identify as a star, cluster, or other object in the night sky. The 1 percent of sightings, which he calls residual UFOs, have attracted his attention. According to Dr. Ross very few astronomers have seen residual UFOs.
The following newspaper excerpt summarizes Dr. Ross's findings:
|“|| In 1969, however, Dr. Ross met two astronomers who were having regular UFO encounters. Both also happened to be involved in occult activity.
Upon investigation, Dr. Ross consistently found a connection between occult involvement and residual UFO encounters. For example, he said, countries with a high degree of occult activity such as Russia during the Soviet era, France, and certain parts of Brazil also had high percentages of UFO encounters. During Russia's Soviet period when every expression of religion except occult activity had been outlawed, he said, “Russians were seeing UFOs at five to eight times the rate Americans were."
Christian apologists who reject naturalistic explanations of life such as the theory of evolution argue that difficult to explain UFOs are spiritual in nature and not amenable to naturalistic explanation. Gary Bates of Creation Ministries International wrote a book entitled Alien Intrusion which gives a biblical Christian perspective on the unscientific notions of extraterrestrial life and UFUlogy.
- This question of back-contamination was a serious worry in the middle years of Project Apollo--that is, the time of the first four missions of that project. NASA, the launch authority for Apollo, required the crews of the first three missions actually to reach the moon to spend weeks in quarantine while under the constant care and watch of a physician. Only after three crews landed on the moon and returned to Earth with no ill effect and no evidence of having contracted any communicable disease on the Moon or in space did NASA drop that requirement. (The crew of Apollo 13 did not face this requirement because their in-flight emergency precluded their planned landing.)
- Donald L. Savage, James Hartsfield, and David Salisbury, "Meteorite Yields Evidence of Primitive Life on Early Mars," Mars Meteorite Project, press release 96-160, August 7, 1996. Retrieved April 17, 2007, from the Jet Propulsion Laboratory Web servers.
- If such life forms survived, that need not be a great shock to any observer. Extremophiles, or microbes known to thrive under conditions that would kill or render dormant any other form of life, are well-known on Earth and have even been the subject of engineering studies attempting to find practical uses for them.
- Rick Lockridge, "Scientists dispute NASA's claims about Mars meteorite", The Cable News Network, January 15, 1998. Retrieved April 17, 2007 from CNN's web servers.
- Authors unknown, "Do Martians Exist?, NASA Mars Exploration, 05 Oct 2005 04:51:40 UTC. Retrieved April 17, 2007, from NASA.
- Everett Gibson, Jr., David S. McKay, and Kathie Thomas-Kerpta, "Life on Mars: Evidence from Martian Meteorites," Proceedings of the Founding Convention of the Mars Society, R. M. Zubrin and M. Zubrin, eds. 1998. Retrieved April 17, 2007, from The Mars Society.
- Crick, F. H. C., and Orgel, L. E. "Directed Panspermia," Icarus, 19, 341 (1973).
- For a detailed discussion on the logical weaknesses and omissions of such a position, see the main article on Panspermia.
- Anonymous, "Project Blue Book", UFO Evidence.org, retrieved April 16, 2007
- Anonymous, The Project Blue Book Archive, retrieved April 16, 2007
- Fund for Unidentified Flying Object Research (FUFOR), Official Site of the National Investigative Committee for Aerial Phenomena, Francis L. Ridge, editor and Webmaster, December 15, 1997 to present. Retrieved April 16, 2007.
- Presumably the Soviet Army Air Forces had their own version of Blue Book as well.
- Home of the SETI Institute
- The Air Force might also have acted in a deceptive manner in certain isolated cases in which what the witnesses took for UFOs were actually secret experimental prototypes. Perhaps some of these prototypes exist today as the B-2, F-117, and other Stealth aircraft.
- I_John 2:2 (NASB)
- Genesis 1:26-28 (NASB)
- Romans 5:14 (NASB)
- For a further exposition of the uniqueness position, see Essay: Extraterrestrial Life and the Bible.
- Farrakhan seems recently to have abandoned this theory and attempted to steer the movement he now leads toward the orthodox Islam taught by Muhammad.
- Willey, David. "Vatican says aliens could exist?" BBC News (London), 13 May 2008. Retrieved August 24, 2008.
- Carter claims to have witnessed an unidentified flying object in 1969; he remains the only U.S. President to have formally reported a UFO. He filed a report with the International UFO Bureau in Oklahoma City after a request from that organization. See Jimmy Carter.
- User "nikbaron". Representative Dennis Kucinich UFO." <http://youtube.com>, posted October 31, 2007. Retrieved November 17, 2007.
- Feagler, Dick. "So Dennis Kucinich saw a UFO; what's the big deal?" The Plain Dealer (Cleveland), October 28, 2007. Retrieved November 17, 2007.
- Authors unknown. "Apollo 14 astronaut claims aliens HAVE made contact - but it has been covered up for 60 years." The Daily Mail (London, England, UK), July 24, 2008. Accessed July 24, 2008.
- Authors unknown. "A UFO 2nd Coming." Let Us Reason Ministries, 2007. Retrieved November 3, 2007.
- Gleghorn, Michael. "UFO's and Alien Beings." Probe Ministries. Retrieved November 3, 2007.
- Tarjanyi, Judy. "Astronomer links UFOs to Occultism." The Toledo Blade, January 4, 2003. Retrieved November 3, 2007.