The hunt for a second Earth: discovering the lightest exoplanet yet
Researchers have identified Gliese 581 e, a planet with only about twice the mass of Earth. This video explores how advanced technology detects tiny stellar wobbles to find worlds that might support liquid water.
Announced by Michel Mayor on 21 April 2009, the discovery of Gliese 581 e marks a milestone in exoplanet research. Located 20.5 light-years away in the Libra constellation, this planet orbits its host star in just 3.15 days. While Gliese 581 e is likely rocky, it sits too close to its star to be habitable.
The research also refined the orbit of Gliese 581 d, a planet first discovered in 2007. Now confirmed to be within the habitable zone, Gliese 581 d is a candidate for a 'water world' that could host deep oceans. These findings were made possible by the HARPS spectrograph at the 3.6-metre ESO telescope in Chile, which can detect stellar wobbles as slow as 7 km/hour.
Source: ESOcast 6: Lightest Exoplanet Found
