Q&A: How to Rate the Habitability of Other Planets
Gliese 581 System This artist's concept shows the inner planets of the Gliese 581 system. Planet G, shown in foreground, is thought to be in its star's habitable zone. Unfortunately, we won't be able to visit other solar systems for a very, very long time, according to a new study. Lynette Cook/via NASAWhat's the most habitable planet? These days, every exoplanet discovery is still rich with excitement, as astronomers scrutinize each distant world and consider its possible characteristics. But this could get tedious pretty soon, as the number of confirmed exoplanets climbs into the thousands. When that happens, astronomers and especially astrobiologists will have to start sifting planets according to their interestingness. A new paper to be published next month describes a new two-step ranking system to make this process easier. We spoke to astrobiologist Dirk Schulze-Makuch to get some details. Unlike other astrobiology criteria, this new system doesn't assume...