In the new issue of Smithsonian, I've got an article about life on Mars. I'm not writing about anything NASA has actually found, but instead about the difficulty of just recognizing life, even if the evidence is in your hand (or in your rover's spectrometer). While the chances of life existing today on the surface of Mars aren't fantastic, a lot of researchers are pretty optimistic that there are fossils to be found. But it turns out that fossils of microbes are even more difficult to identify. You just need to consider some of the fierce debates over some of the oldest fossils on Earth--a topic I've written about before on the Loom here.
Some magazines will only let you see their articles on-line if you subscribe. Sometimes you can read the text for free. Smithsonian, incredibly enough, puts pdf's of their articles online for a month. So if you want the full magazine experience coming out of your own printer, here's your chance. (Just be sure to scroll down to the bottom of the page.)
Update 10 AM: Drat. For some reason the pdf file is not linked. I will see if they plan on making it available and post another update when they do.
Update 10:30 AM: Now the link works, but the pdf is just text. Probably a copyright issue. Oh well. Perhaps my prose will be enough...
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The link to the pdf file of your article on the Smithsonian's page isn't working.
The current link is to the html page. The pdf file is at http://www.smithsonianmag.si.edu/smithsonian/issues05/may05/pdf/mars.pdf
Nice article.
I won't believe any results using microfossils or antibody arrays. All it takes is a little stray dust to wreck the results.
What they need to do is measure the chirality of Martian organic molecules. Dig up bucketloads of dirt, wash its organic gunk out with acetone, distill the solvent down to a single drop of brown sludge, and run it through a liquid chromatograph with a polarimeter detector. If the polarization changes as various molecules come off the column, then living things produced them. (Or could a polarized gamma ray burst synthesize enough chiral molecules to matter?)
I understand where you're coming from, Daniel Newby, but I'm not convinced that life based on non-chiral molecules is impossible. Yes, we need chain molecules with a relatively small alphabet of subunits, but couldn't the subunits all be symmetric?