Earth's cousins: Upcoming missions to look for 'biosignatures' in exoplanet atmospheres
Saturday, February 15, 2020 - 05:00
in Astronomy & Space
Scientists have discovered thousands of exoplanets, including dozens of terrestrial—or rocky—worlds in the habitable zones around their parent stars. A promising approach to search for signs of life on these worlds is to probe exoplanet atmospheres for "biosignatures"—quirks in chemical composition that are telltale signs of life. For example, thanks to photosynthesis, our atmosphere is nearly 21% oxygen, a much higher level than expected given Earth's composition, orbit and parent star.