Methane Confirmed

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silylene old

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The highest concentrations of methane in the equitorial regions IMO supports an abiogenic origin of methane. If methane is being formed by photoreductive processes on metal oxide dust catalysts (a known mechanism!), one would expect that this would occur to the greatest extent in the regions of greatest insolation (Martian equitorial regions).<br /><br />If methane had a biological origin, one would expect the greatest concentrations to occur in the polar regions, where water is in the highest atmospheric concentrations, and ice is closest to the surface. <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>
 
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Leovinus

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Would you expect methane from the coldest regions? I would have thought it would have come from warmer regions where there is the greatest chance of finding liquid water. <div class="Discussion_UserSignature"> </div>
 
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silylene old

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Leo, if methane was of biological origin, I would expect to "follow the water". <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>
 
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larper

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If the credo for the the current rover mission was "follow the water", the credo for the next could be "follow the methane."<br /><br />Whatever the result, a rover mission to discover the source of the methane would be instructive. <div class="Discussion_UserSignature"> <p><strong><font color="#ff0000">Vote </font><font color="#3366ff">Libertarian</font></strong></p> </div>
 
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CalliArcale

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That's a very good point. Life as we know it would have a pretty tough time surviving at the poles, even though there's more *surface* water there. But what if there are comparatively large resevoirs of *subsurface* water elsewhere, perhaps near the equator where it is warmer? This is a question not easily answered right now, of course, as we don't even know whether there is any subsurface water. We know there *was* surface water, but that was a long time ago. Perhaps MARSIS will help shed some light on this, although I'm not going to get my hopes up too high; I suspect the results will be either negative or ambiguous, as I don't think they'd get anything really positive with this kind of an instrument. Just a better idea of where to look with other instruments.<br /><br />One thought.....if methane is produced by any process on Mars, it might not reside in the greatest concentrations near where it was produced. This may seem counterintuitive, but consider that the greatest concentrations of CFCs in the Earth's atmosphere are around the poles -- despite the fact that it's mainly produced at the lower latitudes where most humans live. This produces the ozone holes. It's possible that weather patterns on Mars could obscure the true origin of the methane. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>
 
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astrophoto

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A recent article on SDC stated that the current Martian equator might actually be the best place to locate subsurface water. It discussed how the current equator was once where the liquid water existed and had since relocated. They proposed this based on data they are observing with crater groupings.<br /><br />http://www.space.com/scienceastronomy/050418_mars_equator.html<br /><br />So it may be 'follow the water AND the methane' to the equator.
 
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meteo

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<font color="yellow"><br />One thought.....if methane is produced by any process on Mars, it might not reside in the greatest concentrations near where it was produced. This may seem counterintuitive, but consider that the greatest concentrations of CFCs in the Earth's atmosphere are around the poles -- despite the fact that it's mainly produced at the lower latitudes where most humans live. This produces the ozone holes. It's possible that weather patterns on Mars could obscure the true origin of the methane.</font><br /><br />Brewer-Dobson circulation in the Earth's stratosphere is partially responsible for higher CH4 concentrations equatorward for a given pressure level.<br /><br />http://www.ccpo.odu.edu/SEES/ozone/class/Chap_6/6_Js/6-04d.jpg<br /><br /><font color="yellow">3.5.2 Seasonal Hemispheric Differences in Methane Distribution -- This overall pattern of upward mass transport in the tropics and downward transport in the extratropics due to the Brewer-Dobson circulation cell is reflected in long-lived tracers such as methane (CH4). Figures 6.04a, b, c, and d show methane distribution for January, March, July, and October respectively. Methane has its source region in the troposphere, and is lost in the stratosphere by a reaction with OH molecules and oxygen atoms (thus, it has a distribution opposite to ozone, see Chapter 5). Like with ozone density, the contours of methane density are displaced upward in the tropics and downward at higher latitudes, reflecting the influence of the Brewer-Dobson circulation as shown by the arrows. The ascending branch of the Brewer-Dobson circulation carries high-methane air from the tropical lower troposphere into the tropical stratosphere, while the descending branch of the Brewer-Dobson circulation carries low-methane air from the polar upper stratosphere into the polar lower troposphere.<br /><br />Figures 6.04a and 6.04c show l</font>
 
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igorsboss

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As I recall, one part of the Gaia theory was a corollary concerning the detection of life on distant planets by examining the planetary atmosphere.<br /><br />That corollary said that one signature of life was the presence of mutually unstable molecules in the same atmosphere.<br /><br />For example, the presence of CH4 in Earth's atmosphere is a clear indication of life, BECAUSE Earth's atmosphere also contains abundant O2, which would oxidize the CH4 over time.<br /><br />But on Titan, the presence of CH4 is not a clear indication of life, because Titan's atmosphere does not also contain O2.<br /><br />What does the presence of CH4 say about Mars? The Martian atmosphere does not contain abundant O2. Does it contain enough O2 to oxidize the available CH4? How long can CH4 last on Mars?
 
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silylene old

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Adding some additional references on the photoreduction of CO2 or CO with hydrogen to form methane, over metal oxide dust catalysts:<br /><br />Research on Chemical Intermediates<br />Volume 26, No. 1, p. 93<br />"Photoreduction of carbon dioxide by hydrogen and methane<br />T. Tanaka, Y. Kohno and S. Yoshida"<br /><br />"Photochemical reduction of CO2 using Cu-loaded silicate rock powder suspended in water<br /><br />Kiyohisa Ohta, Youko Ueda, Satoshi Nakaguchi, and Takayuki Mizuno <br />Can. J. Chem./Rev. Can. Chim. 76(2): 228-233 (1998) "<br /><br />"I-H. Tseng, W.-C. Chang, J. C. S. Wu, "Photoreduction of CO2 using Sol-Gel-Derived Titania and Titania-Supported Copper Catalysts," Applied Catalysis B: Environmental, vol. 37(1), 37-48, 2002. "<br /><br />"E. Fujita, Photochemical Carbon Dioxide Reduction with Metal<br />Complexes, Coordination Chemistry Review, vol. 18.5186, 373-384, 1999; N. Sutin, C. Creutz.<br />and E. Fujita, Photo-Induced Generation qf Dihydrogen and Reduction of Carbon Dioxide Using<br />Transition Metal Complexes, Comments Inorg, Chem. vol. 19,67-92, 1997; T. Inui, M. Anpo.<br />K. Izui, S. Yanagida, and T. Yamaguchi (Eds.) Advances in Chemical Conversions for<br />Mitigating Carbon Dioxide, Studies in Surface Science and Catalysis, Vol. 114, Amsterdam,<br />Elsevier, 1998." <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>
 
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phaze

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<font color="yellow">Many types of microbes here on Earth produce a signature of methane. Indeed, the tiny fraction of atmospheric carbon found as methane on our planet is churned out almost entirely biologically with only a very small contribution from abiotic processes, scientists say.</font><br /><br />I'm curious, have we heard any numbers quantifying the amount of Methane found on Mars?<br /><br />My understanding of this is VERY crude... but I'm thinking of it in terms like this:<br /><br />1. We detect globs of Methane on Mars in quantities of X.<br /><br />2. On Earth we see globs of Methane in quantities of Y.<br /><br />3. We know that on earth only a small % of Y is from abiotic processes... so say that works out to quantity A.<br /><br />4. We then compare A to X and make some comments...<br /><br /><br />Now I know conditions on both planets are vastly different, etc., etc., etc.... but I think there should be some value in comparing these numbers.<br /><br />Are these amounts (concentrations?) on Mars consistent with a faint earth-like abiotic processes on Mars... or would they require an active Earth-like volcano (or whatever produces abiotic methane on earth) every 100 yards?<br /><br />Can this methane be quantified in any manner similar to what I'm talking about?<br /><br /><br />Thanks.<br /><br /><br /><br /><br /><br /><br /><br /><br /><br />
 
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meteo

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On Mars the lifespan for Ch4 is 300-450 years. On Titan it's ten million years, replaced by methane from the hydrocarbon seas/goo. I think it's the UV radiation that determines how long the CH4 lasts. On Mars and Titan I believe the thinking is UV and not oxygen that breaks up most methane, especially the higher you go.
 
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silylene old

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reikel: I posted some better papers on this subject in these forums several months ago, shortly after the forums' wipe.<br /><br />Most of these papers cited above are about lab-reactions, not about geological-condition reactions. They were done by chemists looking for new routes to forming methane, rather than as atmospheric chemists exploring abiological production of methane. So I don't know how useful these works they would be for estimating methane production in the atmosphere, other than to suggest that it might be possible.<br /><br />Previously I did post a very good paper posted here (pre-wipe) which estimated the amount of NH3 produced by photoreduction of N2 over certain metal-oxide sands (which act as catalysts). Interestingly, the amount of abiological NH3 produced by this method was just about right for Mars. <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>
 
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starbaby57

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What kind of technology and platform are we talking for the next phase of surface or orbital methane hunting?<br />Is it even possible from orbit to narrow down the source to an area of several square kilometers or are we left with "sniffing" on the surface to catch a "down-wind" scent of methane and zig-zag hoping to zero in on the source? I imagine we are talking IR from low orbit and gas chromatography from the surface but those are just from my limited knowlege. Does anyone know of some of the next steps being tossed around as we perhaps change over to a "follow the methane" strategy?
 
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soulseeker

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I believe that the Methane points to some form of life on mars. <br /><br />Considering there are very few signs of any type of thermal activity going on so there is really no other explanation for it. <br /><br />Of course people can make up some lame theory like so many do. The probes of the seventies found that life existed on mars so this is nothing new but it does make a much stronger case.
 
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