Martian Methane from Photolysis? (Icarus)

[paulanderson]

This is for silylene in particular. <img src="/images/icons/wink.gif" /><br /><br /><b>Methane on Mars: A Product of H2O Photolysis in the Presence of CO</b><br />http://tinyurl.com/rbocu<br /><br />I saw another longer version of this somewhere but can't find the link again now. This abstract is shorter, but gives the basic idea still.

 

[yevaud]

We had a discussion about this here previously. I'll try to locate the thread again for you. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[yevaud]

Dang. Can't quite locate it. I'll PM a few people and see if they remember the name and time frame of the debate. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[larper]

Don't you get Matrian methane from Matrian snakes? <div class="Discussion_UserSignature"> <p><strong><font color="#ff0000">Vote </font><font color="#3366ff">Libertarian</font></strong></p> </div>

 

[yevaud]

Yes, but you have to have an "Extra Sense" to locate the Matrian Snakes.<br /><br /><img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[paulanderson]

Yes, I remember the previous discussion (and posted there also, but couldn't find it either), although this newest abstract was just published more recently (and listed as a news item), so just wanted to point it out, as silylene had said that there had apparently been little, if any, publicized mention of this theory in the science community.

 

[yevaud]

Well, for a simple sentence or so, the Abstract does lend support to the main emphasis of that prior debate - that the presence of Methane in the Martian atmosphere is due to some simple and non-biological causes. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[paulanderson]

I found the previous slightly longer abstract I was thinking of before; this one covers the possibility of clathrate hydrates:<br /><br /><b>Interglacial Clathrate Destabilization on Mars: Possible Contributing Source of its Atmospheric Methane</b><br />http://www.gsajournals.org/gsaonline/?request=get-abstract&doi=10.1130%2FG22311.1<br /><br />Also just saw this new article from <i>American Scientist</i>, covering a variety of theories, including serpentinization, biology, etc.:<br /><br /><b>Life on Mars?</b><br />http://www.americanscientist.org/template/AssetDetail/assetid/49613<br /><br />What's interesting, is that even if it say "just" serpentinization, that process requires liquid water (evidence for hydrothermal activity?), going by what I've read so far on the subject including this new <i>American Scientist</i> article, which again has implications for any possible Martian biology. Could you elaborate on this again at all, silylene?

 

[yevaud]

While we're waiting for him to appear...<br /><br /><i>A key consideration is that methane on Mars must be replenished by a current or recent source because it's an unstable gas broken down by ultraviolet radiation. On Mars, methane molecules typically survive about 340 years. Achieving a balance between the rate of methanogenesis and the rate that methane breaks down would be the crux of any calculation.</i><br /><br />Perhaps one of the key indicators of subsurface liquid H20, I'd think. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[silylene old]

Thanks. I had seen this on unmannedspaceflight.com<br /><br />I have a copy of the paper that Alex blackwell was kind enough to send me shortly after it published. I may post an interesting data graph from their paper - it is quite compelling. The authors have carried out experiments photolyzing various gas mixtures and proved small amounts of CH4 can form. I have their paper on my work computer, not at home.<br /><br />Their mechanism differs from my proposal: They propose a photoreductive process from CO, whereas I proposed a photoreductive process over catalytic amounts of metal oxide dusts from CO2.<br /><br />I do think both hypotheses are feasable. I do think the CH4 yields would be higher over the metal oxide dusts.<br /><br />I also think both mechanisms are far more likely than any biogenic proposal. The photoreductive mechanism for CH4 also nicely accounts for the observation that CH4 production is highest in the Martian areas which receive the greatest insolation. <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>

 

[cosmictalk]

geological sources is what caused biological sources here on earth, right ?