DEEP INTO HER WORK.

Microbiologist and IMAX star Hazel Barton dives -- and climbs and rappels and crawls -- into uncharted caves to stalk rare life-forms. The air is chilly and dank and her entire person -- miner's helmet, coveralls, hiking boots and the pink "Barbie" lunch box in which she totes the field tools of a microbiologist -- is caked with brown clay. After six hours of climbing and squirming through Black Chasm, a 4,000-foot-long cave carved from marble bedrock in the heart of gold-rush country 65 miles east of Sacramento, Calif., Barton has reached what she calls her "icked-out" point. The Black Chasm trip was a tame one by her standards, but on this day Barton, who's also a full-time scientist, wasn't just seeking a rush. The purpose of the trip: Barton collected samples from water corrosion sites on rock never before touched by human hands in order to examine them for signs of life. Barton, who left a research position at the University of California-Davis last month for an assistant professorship in biological sciences at Northern Kentucky, hunts for extremophiles, microbes that thrive in conditions once thought to be inhospitable to life.