Looking for Life on Mars, on Earth

Wired has an interesting writeup about astrobiologist Chris McKay's efforts to find evidence of life in the high desert of the Atacama, Chile.

I was surprised to learn just how sterile the Atacama is. Despite the discovery in recent decades of "extremophiles," it appears that there are limits to what hardy microbial life can tolerate, even on Earth. Learning how to detect the trace amounts of life, preventing forward contamination of the test site and contamination of gathered samples, and determining where to find any trace life are all skills that will serve the first human explorers of Mars well.