Could life survive, even flourish, in boiling, acidic water? Inside solid rock, or ice? In the near-vacuum of space? As part of the Toronto Science Festival, I'll be moderating a panel on "Life in Extreme Environments" with astrobiologist Kevin Hand, geochemist Barbara Sherwood Lollar, and oceanographer John Baross. The panel is at the University of Toronto, this Saturday at 4:00 p.m.