I'd like to see the full article to understand more. The abstract seemingly dismisses geological sources without much justification, and doesn't discuss the olivine thermal degradation mechanism. <br /><br />(And he never thought of photoreductive mechanisms to form methane.) <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>