Monday, May 30, 2011

Life in Space? Exoplanet Habitable Zone Could Be Wider

Planet hunting is by far the hottest area of astronomy these days, and just about everyone who's in on the search is looking for the same thing: a distant world where life could exist, at least in theory. That means a world more or less the size of Earth, orbiting its parent star in the habitable zone — the location, just the right distance away from its sun's heat, where water can exist in liquid form. Size or distance alone aren't good enough: an Earth-size planet that's too hot or too cold probably couldn't support life, and a giant gasbag like Jupiter couldn't either, even if its temperature were ideal.

It's a pretty strict set of requirements — but maybe not as strict as scientists have assumed. Two new studies, one purely theoretical and the other focused on a known exoplanet, suggest that planets that would on first blush seem too cold to harbor life may be balmier than expected. That means the habitable zone could be a lot wider, and the prospects for alien life more favorable, than anyone thought.

http://www.time.com/time/health/article/0,8599,2073211,00.html?xid=newsletter-weekly