For the 1st time, humans have found evidence of liquid H₂O on an #extrasolar planet in a star's #habitable zone. This plot shows the 1.4µm vibrational bands of H₂O vapor. Pressure & temperature in the deeper atmo likely allow liquid H₂O. Benneke+ 2019: https://t.co/KmreOVJiUppic.twitter.com/tMvKSF8UDf
K2-18b receives only 5% more radiation than the Earth, leaving it with an equilibrium temperature of 265 K. This is the coolest exoplanet that we've detected water in. While not a true Earth-analogue due to its size, this bodes well for our exploration of small planets. pic.twitter.com/SrAXA5yPgz