The Atmosphere of Pluto
http://www.astrobio.net Download time: Apr 20 2011 8:51 AM ET
A British-based team of astronomers has discovered carbon monoxide gas in the atmosphere of Pluto, after a worldwide search lasting for nearly two decades. Team leader Dr. Jane Greaves of the University of St. Andrews presented the new discovery in her talk on Wednesday 20 April at the National Astronomy Meeting in Venue Cymru, Llandudno, Wales.
Pluto was discovered in 1930 and then considered as the Sun's smallest and most distant planet. Since 2006 it has been regarded by astronomers as a 'dwarf planet', one of a handful of such bodies with sizes of hundreds of kilometers that orbit in the distant reaches of the Solar System, out beyond Neptune.
Pluto is the only dwarf planet known to have an atmosphere, found in 1988 when it dimmed the light of a distant star before Pluto passed in front of it.The new results, obtained at the 15-meter James Clerk Maxwell Telescope in Hawaii, show a strong signal of carbon monoxide gas.
Previously the atmosphere was known to be over a hundred kilometers thick, but the new data raise this height to more than 3,000 kilometers -- a quarter of the way out to Pluto's largest moon, Charon. The gas is extremely cold, about -220 degrees Centigrade. …
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