K2-18b, which is eight times the mass of Earth, is now the only exoplanet known to have both water and temperatures that could support life. The discovery is the first successful atmospheric detection for an exoplanet orbiting in its star’s ‘habitable zone’, at a distance where water can exist in liquid form.
“The composition of a rocky planet is one of the most important missing pieces in our efforts to find out whether a planet is habitable or not,” said Haiyang Wang with the Australia National University Research School of Astronomy and Astrophysics (RSAA).
