Under Pressure: How the Density of Exoplanets' Atmospheres Weighs on the Odds for Alien Life

08/05/2013 15:22

At this early stage in the search for extraterrestrial life in our solar system and beyond, the emphasis is on liquid water. Where it can exist on a planet’s or moon's surface, so the thinking goes, life as we know it has a chance. Much of the observational and theoretical work in astrobiology therefore concerns the "habitable zone," the orbital band around stars where a rocky world's water neither freezes away nor boils off. [Read more] ...