Fossil Hunter's guide to Mars

I worked directly with Charles Shults as he wrote the book A Fossil Hunter's Guide to Mars, critiquing everything, proofreading, and even came up with the name for the book. So, I am very glad to see that he's getting some mainstream media exposure for his work. When he first told me he had found fossils on Mars in the Spirit and Opportunity images, I was skeptical but at least willing to see the evidence. The clincher for me was this image, taken by the rover Opportunity on Sol 111. In the bottom left corner of that NASA image you see the image at the right. That rock exhibits fivefold radial symmetry. That is, if you rotate that rock in increments of 72 degrees the pattern facing us looks the same. There is no geological process that produces rocks of this kind, no mineral with this kind of symmetry occurs in nature (although such quasicrystals are possible in tightly controlled laboratory settings, they are microscopic). The only way for such a rock to ever appear is if a life form (such as a starfish) becomes fossilized. Therefore, fossils exist on Mars. Not convinced? You can buy the book and check the evidence (presented in exhaustive detail) for yourself.