Scientists plumbing the bubbling, black depths of a geothermal hot spring in Idaho have discovered a unique community of microbes that thrive without sunlight or oxygen. … In light of the findings, researchers said the question should no longer be whether extreme life exists on Mars and elsewhere. "Rather, did life originate there, or was it transplanted from Earth?" said University of Colorado planetary scientist Bruce Jakosky.

Blind shrimp, mammoth white clams, brown hairy snails—they're among 300 species that marine biologists have discovered in the last 20 years. They thrive around deep-sea volcanic hot springs.

We're going to take a quick break and come back and talk lots more about these extreme, extreme conditions and extreme life forms that can live there, and meet a guy who actually goes out and looks for them in, of all places, one of the biggest national parks.