Auroras
Auroras You are outside on a clear summer night, when all of a sudden a flash catches your eye. ... The auroras center around the magnetic poles of Earth. ... The philosopher Xenophanes believed that the auroras were an “accumulation of moving and burning clouds” (http://virtual. ... Evidence of valid scientific proof of the causes of auroras, however, did not really begin to appear until the late 18th century. ... However, relevant scientific documentation of the causes of auroras was not achieved until over a century later when Jean Jacque Dortous de Mairan of France related auroral displays to solar activity in 1774. ... This led to the belief that, “the sunspots probably eject “particles” (later the word electrons was substituted), which on striking Earths atmosphere cause the auroras” (http://www. ... A few years after this, in 1860, Elias Loomis of Yale University created a map that showed how many times, on average, auroras were observed each year in different locations. ... Elias Loomis’ map Elias Loomis Hermann Fritz compiled a more accurate map eleven years later, in 1881: Hermann Fritz’s map Hermann Fritz At the turn of the century, Kristian Birkeland developed the first controlled scientific experiment addressing the cause of auroras on earth. ... Kristian Birkeland and his “terella” Although research on auroras continued, substantial progression was not very evident until 1954, when auroral electrons were actually observed. ... This accomplishment led to further intensified research and study of the atmosphere and the auroras. ... Since then, several small discoveries have been made, including evidence that the northern and southern auroras are caused by electrons from the same source, explaining why the images in the north and south polar regions occur simultaneously and often mirrored. ... Locations of Auroras Auroras occur mostly in the Arctic and Antarctic regions of the earth. In the south, auroras are referred to as aurora australis, or southern lights. ... Auroras change in intensity from night to night, but the best viewing hours are from late night through early morning, although auroras may happen anytime during the day. ... The above guidelines refer to the auroras that occur in our own Earth’s atmosphere, but, with the aid of the Hubble Space Telescope in the 1970s, it became evident that auroras occur elsewhere in our Universe. ... However, on these planets, the auroras look pink, due to large amounts of hydrogen in their atmospheres. The following are images of Auroras on Jupiter: Jupiter, in particular, produces interesting auroras, because they are not caused by solar power, but “are generated instead by volcanic particles from the Jovian moon Io” (http://astrobulletin. ... The auroras produced on Jupiter are, “many times more powerful that those on Earth” (http://astrobulletin. ... The unique characteristic of auroras on Earth, however, is their tendency to be green in color. ... With this in mind, observing the coloration of auroras on other planets is one way to explore signs for other, potentially habitable worlds. “If a distant, unknown planet has shimmering green auroras, thats a strong indication that its atmosphere is rich in oxygen, perhaps enough to support life” (http://astrobulletin. ... Auroras occur in the Earths atmosphere at high altitudes, but, as mentioned above, they can also occur on other planets as well.