Changes

Observational evidence for the Milky Way being made up of distant stars first came when [[Galileo Galilei]] pointed his [[telescope]] towards the Milky Way, observing a large amount of faint stars.<ref>http://www-gap.dcs.st-and.ac.uk/~history/Biographies/Galileo.html</ref>  [[William Herschel]] in 1785 was the first to attempt to map out the shape of the Milky Way.  He created a diagram based on counting the stars in the different regions of the sky, giving a rough shape of the galaxy with the Solar System near the center.  It wasn't until [[Harlow Shapley]] in the end of the 19th century was the Milky Way was discovered to be a flat disk with the Solar System far from the center.<ref>http://www.scientificamerican.com/article.cfm?id=how-did-scientists-determ</ref>

Observational evidence for the Milky Way being made up of distant stars first came when [[Galileo Galilei]] pointed his [[telescope]] towards the Milky Way, observing a large amount of faint stars.<ref>http://www-gap.dcs.st-and.ac.uk/~history/Biographies/Galileo.html</ref>  [[William Herschel]] in 1785 was the first to attempt to map out the shape of the Milky Way.  He created a diagram based on counting the stars in the different regions of the sky, giving a rough shape of the galaxy with the Solar System near the center.  It wasn't until [[Harlow Shapley]] in the end of the 19th century was the Milky Way was discovered to be a flat disk with the Solar System far from the center.<ref>http://www.scientificamerican.com/article.cfm?id=how-did-scientists-determ</ref>

Although the [[Andromeda galaxy]] was recorded as long ago as the 10th century, and both it and the [[Magellanic Clouds]] were known perhaps since ancient times, historically they were not seen as other galaxies, but as nebulae.  In 1917, Heber Curtis observed a [[nova (star)|nova]] in what was then called the "''Great Andromeda Nebula''", that along with previous novae found based on subsequent photographic evidence, discovered they were ten magnitudes fainter then novae events in our own galaxy.  based on this new evidence, he became a proponent of the "'''island universe hypothesis'''" first proposed by [[Immanuel Kant]] in 1755, that the spiral nebulae were actually other galaxies.<ref>http://adsabs.harvard.edu/abs/1988PASP..100....6C</ref>  This was later proven by [[Edward Hubble]] in the 1920s, when he was able to determine the distance to the other galaxies though using [[Cepheid variables]] located within them as standard candles to determine their distance, showing the "nebulae" were too distant to be part of the Milky Way and hence other galaxies.<ref>http://adsabs.harvard.edu/cgi-bin/bib_query?1929ApJ....69..103H</ref>

Although the [[Andromeda galaxy]] was recorded as long ago as the 10th century, and both it and the [[Magellanic Clouds]] were known perhaps since ancient times, historically they were not seen as other galaxies, but as nebulae.  In 1917, Heber Curtis observed a [[nova (star)|nova]] in what was then called the "''Great Andromeda Nebula''", that along with previous novae found based on subsequent photographic evidence, discovered they were ten magnitudes fainter then novae events in our own galaxy.  based on this new evidence, he became a proponent of the "'''island universe hypothesis'''" first proposed by [[Immanuel Kant]] in 1755, that the spiral nebulae were actually other galaxies.<ref>http://adsabs.harvard.edu/abs/1988PASP..100....6C</ref>  This was later proven by [[Edwin Hubble]] in the 1920s, when he was able to determine the distance to the other galaxies though using [[Cepheid variable]]s located within them as standard candles to determine their distance, showing the "nebulae" were too distant to be part of the Milky Way and hence other galaxies.<ref>http://adsabs.harvard.edu/cgi-bin/bib_query?1929ApJ....69..103H</ref>

==Environment of the Milky Way==

==Environment of the Milky Way==