Martian clay deposits may contain new evidence for past life

[paulscottanderson]

<p><span style="font-family:LucidaGrande;font-size:11px;white-spacere-wrap;-webkit-border-horizontal-spacing:2px;-webkit-border-vertical-spacing:2px" class="Apple-style-span">This is interesting; the discovery by Mars Reconnaissance Orbiter of clay deposits in Mawrth Vallis which contain a layer of reduced (ferrous) iron, which, according to Janice Bishop, team leader of a new study just published in the journal <span style="font-style:italic" class="Apple-style-span">Science </span>(August 8, 2008), <span style="font-style:italic" class="Apple-style-span">usually</span> involves microbes.</span></p><p><span style="font-family:LucidaGrande;font-size:11px;white-spacere-wrap;-webkit-border-horizontal-spacing:2px;-webkit-border-vertical-spacing:2px" class="Apple-style-span">Not proof of anything yet, and there may be alternative explanations, but it's another piece of the puzzle...</span></p><p><span style="font-family:LucidaGrande;font-size:11px;white-spacere-wrap;-webkit-border-horizontal-spacing:2px;-webkit-border-vertical-spacing:2px" class="Apple-style-span">http://www.space.com/scienceastronomy/080807-mars-clay-02.html<span style="font-family:Verdana;font-size:10px;white-space:normal;-webkit-border-horizontal-spacing:0px;-webkit-border-vertical-spacing:0px" class="Apple-style-span">&nbsp;</span></span></p><p><span style="font-family:LucidaGrande;font-size:11px;white-spacere-wrap;-webkit-border-horizontal-spacing:2px;-webkit-border-vertical-spacing:2px" class="Apple-style-span">Paul</span></p> <div class="Discussion_UserSignature"> <p><font size="1"><span style="font-weight:bold" class="Apple-style-span">-----------------</span></font></p><p><font size="1"><span style="font-weight:bold" class="Apple-style-span">The Meridiani Journal</span><br />a chronicle of planetary exploration<br />web.me.com/meridianijournal</font> </p> </div>

 

[JonClarke]

<p>It's a very interesting paper, ahtlough it shows the not uncommon bias towards volcanism, hydorthermal activity, and acidity.</p><p>Jon</p> <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[paulscottanderson]

<p>Jon,</p><p>Can you comment a bit on the ferrous iron aspect? I realize there are different ways to produce it, but how commonly are deposits produced by microorganisms (on Earth)? Is Janice Bishop right about that? If so, I'd think there's be more discussion about this...</p><p>Paul</p> <div class="Discussion_UserSignature"> <p><font size="1"><span style="font-weight:bold" class="Apple-style-span">-----------------</span></font></p><p><font size="1"><span style="font-weight:bold" class="Apple-style-span">The Meridiani Journal</span><br />a chronicle of planetary exploration<br />web.me.com/meridianijournal</font> </p> </div>