I've been busily working on an aspect of the blog's September 6th anniversary celebration, and I don't want to break away from it. Thankfully regular commentator Will_in_Chicago left a very useful link today...
"We may all be Martians.The full Space.com article goes into several paragraphs of greater detail, and can be read here.
Evidence is building that Earth life originated on Mars and was brought to this planet aboard a meteorite, said biochemist Steven Benner of The Westheimer Institute for Science and Technology in Florida.
An oxidized form of the element molybdenum, which may have been crucial to the origin of life, was likely available on the Red Planet's surface long ago, but unavailable on Earth, said Benner, who presented his findings today (Aug. 28; Aug. 29 local time) at the annual Goldschmidt geochemistry conference in Florence, Italy."