In reply to Jones Beene's message of Wed, 16 Dec 2009 14:43:57 -0800: Hi, [snip]
>http://cosmiclog.msnbc.msn.com/archive/2009/12/16/2152989.aspx I think they're stretching it a bit to call this a water world. You can get the same mass and size figures from a rocky world with a thick atmosphere. I.e. Rrock ~= 12000 km; Ratm ~= 5000 km; Density of rock is taken as the same as the density of the Earth. I have neglected the mass of the atmosphere (Earth's atmosphere only contributes 1 part in a million to the mass of the Earth; even if this planets atmosphere contributes a much larger proportion, it is still relatively trivial. My guess for atmospheric composition would be a CO2/N2 mix. Heavy gasses like CO2 are easier for a planet to hang on to which helps explain such a thick atmosphere. Both gasses would be supercritical at the rocky surface. [snip] Regards, Robin van Spaandonk http://rvanspaa.freehostia.com/Project.html
