Hycean planets are a new class of habitable exoplanets covered with oceans and hydrogen-rich atmosphere. Their radius is more than twice that of the Earth and have ten times its mass. Their average atmospheric temperature almost reaches 200 C. These planets have a rocky core that accounts for at least 10 per cent of the mass of the planet and a water layer that makes up the rest of the mass.
Researchers believe that studying these planets may be the key to finding extraterrestrial life. They estimate that the first biosignature will be detected within two to three years if these planets hold life. The James Webb space telescope, which is to be launched in November, could help the probe.