Astronomers have named a new class of planets on which life is possible.
Researchers at the Cambridge Institute of Astronomy, led by Dr. Nikku Madhusudhan, have suggested that life can be sought not only on Earth-like planets, but also on hot, completely ocean-covered, hydrogen-rich atmospheres.
The new study took K2-18b as a sample, an exoplanet from the red dwarf K2-18, which lies about 111 light-years from Earth: it orbits a star in 33 days and contains water in the atmosphere.
There are many more planets of this type than those similar to Earth. Previously, scientists attributed them to super-Earths or mini-Neptuns, depending on their density. Most minineptuns are about 1.6 times larger than Earth. Most of the scientific community believes that such planets are too large to have rocky depths, and the temperature under their atmosphere is too high to support life.
The researchers analyzed the conditions on such planets depending on their position and the properties of the parent star, and came to the conclusion that they may have microbial life, similar to that found in the most extreme aquatic environments of the Earth. This class of planets was proposed to be named Hycean.
The Hycean planets open up entirely new possibilities for finding life elsewhere. Previously, when we were looking for various molecular signatures, we focused on planets like Earth, which was a smart start. But we think the Hycean planets offer a better chance of finding traces of life.
Nikku Madhusudhan, study author