- uploaded: Aug 15, 2013
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Alternative Ending forgot to put ending in so made the Alternative Ending 1 Oct 2013: Closest Approach to Mars 28 Nov 2013: Closest Approach to the sun 26 Dec 2013: Closest Approach to Earth? (Only if it survives solar encounter) Sometime in late July or early August, the comet will pass what's called the frost line, some 230 to 280 million miles away from the sun, when it will feel enough radiation from the sun that water will begin to evaporate and the comet will appear brighter. Some comets have broken up upon crossing the frost line. On June 13, 2013, the Spitzer imaged Comet ISON with its Infrared Array Camera and observed carbon dioxide - along with dust - evenly spewing away from the comet's nucleus. This, in turn, is creating a spectacular tail which could be as much as 186,400 miles long. That's more than half the distance between the Earth and Moon! "We estimate ISON is emitting about 2.2 million pounds (1 million kilograms) of what is most likely carbon dioxide gas and about 120 million pounds (54.4 million kilograms) of dust every day," said Carey Lisse, leader of NASA's Comet ISON Observation Campaign and a senior research scientist at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland. "Previous observations made by NASA's Hubble Space Telescope and the Swift Gamma-Ray Burst Mission and Deep Impact spacecraft gave us only upper limits for any gas emission from ISON. Thanks to Spitzer, we now know for sure the comet's distant activity has been powered by gas." At the time of this observation, Comet ISON was positioned about 312 million miles from the Sun - or about 3.35 times farther than Earth. "These fabulous observations of ISON are unique and set the stage for more observations and discoveries to follow as part of a comprehensive NASA campaign to observe the comet," said James L. Green, NASA's director of planetary science in Washington. "ISON is very exciting. We believe that data collected from this comet can help explain how and when the solar system first formed." So what of Comet ISON? Right now, scientists theorize the comet is about the size of a small mountain and could be around 3 miles in diameter and weigh between 7 billion and 7 trillion pounds. It is widely accepted at this point that C/2012 S1 is making its first pass through our solar system and will pass within 724,000 miles of the Sun on November 28, 2013. As it nears perihelion, its mix of gases are heating up and disclosing themselves to monitoring equipment located both here on Earth and in space. According to researchers, carbon dioxide could well be the gas that powers emission for most comets located between the orbits of Saturn and the asteroids. When it was discovered by Vitali Nevski and Artyom Novichonok at the International Scientific Optical Network (ISON) near Kislovodsk, Russia, comet ISON was located roughly between the orbits of Saturn and Jupiter - and its abundance of carbon dioxide may have made this early detection possible. "This observation gives us a good picture of part of the composition of ISON, and, by extension, of the proto-planetary disk from which the planets were formed," said Lisse. "Much of the carbon in the comet appears to be locked up in carbon dioxide ice. We will know even more in late July and August, when the comet begins to warm up near the water-ice line outside of the orbit of Mars, and we can detect the most abundant frozen gas, which is water, as it boils away from the comet.