New data suggests the planet may have potentially water-covered surfaces, with a hydrogen-rich atmosphere.
Carbon dioxide and methane has been detected in the atmosphere of exoplanet K2-18 b – a potentially habitable world more than eight times the size of Earth.
The ground-breaking discovery means K2-18 b may belong to a unique class of exoplanets known as “Hycean” planets, which possess hydrogen-rich atmospheres and potentially water-covered surfaces, making them candidates for life.
The initial insights by NASA’s James Webb Telescope were made possible by observations from NASA’s Hubble Space Telescope.
K2-18 b orbits a cool dwarf star called K2-18 about 120 light years away from Earth – within the constellation Leo – and sits within the habitable zone.
These exoplanets, with sizes between Earth and Neptune, are not found in our solar system, making their characteristics a subject of active debate among scientists.
The idea that K2-18 b could be a Hycean exoplanet is particularly fascinating to scientists, with some experts believing that such planets may offer favourable conditions for life to develop.
Nikku Madhusudhan, an astronomer at the University of Cambridge and lead author of the study, said: “Our findings underscore the importance of considering diverse habitable environments in the search for life elsewhere.