Beyond the habitable zone: Exoplanet atmospheres are the next clue to finding life on planets orbiting distant stars
Morgan Underwood, Ph.D. Candidate in Earth, Environmental and Planetary Sciences, Rice University
When astronomers search for planets that could host liquid water on their surface, they start by looking at a star’s habitable zone. Water is a key ingredient for life, and on a planet too close to its star, water on its surface may “boil”; too far, and it could freeze. This zone marks the region in between.
But being in this sweet spot doesn’t automatically mean a planet is hospitable to life. Other factors, like whether a planet is geologically active or has processes that regulate gases in...