Description
K2-18b , also known as EPIC 201912552 b , is an exoplanet orbiting the red dwarf K2-18, located 124 light-years (38 pc) away from Earth. The planet, initially discovered with the Kepler space telescope, is about eight times the mass of Earth, and is thus classified as Mini-Neptune. It has a 33-day orbit within the star's habitable zone, meaning that it receives about a similar amount of starlight as the Earth receives from the Sun and could have similar conditions, which allow the existence of liquid water.
In 2019 the presence of water vapour in K2-18b's atmosphere was discovered, drawing attention to this system. K2-18b has been studied as a potential habitable world that, temperature aside, resembles more a gas planet like Uranus or Neptune than Earth.
In 2023, the James Webb Space Telescope detected carbon dioxide and methane in the atmosphere of exoplanet K2-18b. Webb's data suggest the planet might be covered in ocean, with a hydrogen-rich atmosphere.
