meteo- that is interesting!<br /><br />In view of the fact that earth has so much water and earth's crust has so much CO2 locked in carbonates indicating early earth's huge atmospheric CO2 content.<br /><br />Did earth once have methane in the atmosphere which was then converted....?<br /><br />I doubt it, btw - the early rocks indicate very early water.<br /><br />However, early earth was hot!<br /><br />BTW- oxygen is the most abundant element in earth's crust- which may mean early earth had oxygen which oxidized some of these minerals.<br /><br />However, I do believe early Iron deposits show less oxidation.<br /><br />One must get the timing right, of course.<br /><br />Titan is cold, earth was hot. The higher temperature would have made short work of converting methane to carbon dioxide and water.<br /><br />Still, it is interesting! Was there some point, a flash point, where earth was on fire?