Gliese 581g is an exoplanet located about 20.3 light-years away in the constellation Libra. It orbits the star Gliese 581, which is a red dwarf. Discovered in 2010, Gliese 581g is notable for being within the star's habitable zone, where conditions might allow for liquid water to exist. The planet is roughly 3 to 4 times the mass of Earth, suggesting it could be a rocky planet. Its potential for habitability has made it a subject of interest in the search for extraterrestrial life, although further studies are needed to confirm its characteristics and atmosphere.