At http://phys.org/print293793112.html … there is some nice information on Titan, a moon of Saturn, and puzzles associated with it liquid constituents.
At www.jpl.nasa.gov/news/news.php?release=2013-231&cid=release_2013-231 … we learn that the Spitzer Space Telescope has observed what are thought to be strong carbon dioxide emissions from Comet ISON as it approaches the inner solar system. A trail of gas and dust 300,000km in length, has been seen. The comet is about 3 miles in diameter and the size of a small mountain. The NASA news release then says, 'like all comets, ISON is a dirty snowball made up of dust and frozen gases … such as water, ammonia, methane, and carbon dioxide …' – have they forgotten the two space probes to comets that were not dirty snowballs? Does theory outweigh observation in astronomy – what is going on? Did they feel duty bound to come out with the consensus trite comment as they compound things by then adding, 'it is the first passage from the distant Oort Cloud …. ' which is another theoretical consensus view. How do they know this is the first time this comet has visited the inner solar system or that it has an origin in a cloud of comets yet to be actually observed? NASA claims the comet is warming up as it gets closer to the Sun and different gases are heating up at different temperatures, the point of evaporation. Carbon dioxide is thought to be the gas that powers emissions from most comets as they approach and enter the region between Saturn and the Asteroid Belt. It won't reach the water/ice line until it is near Mars – in late July or during August. We await what happens as this is getting rather interesting. Is another consensus theory about to blow its top.