Exoplanet with Methane and Carbondioxode in environment detected
New Delhi : A team of space researchers at University of Cambridge came out with data from the NASA/ESA/CSA James Webb Space Telescope to claim presence of methane and carbon dioxide in the atmosphere of K2-18 b, an exoplanet situated in the habitable zone. It gets interesting with the fact that this is the first time when carbon-based molecules have been found on an exoplanet in the habitable zone.
K2-18 b, eight times the mass of Earth, orbits the cool dwarf star K2-18 and is located 110 light years away in the Leo constellation. The discovery implies a hydrogen-rich atmosphere covering an ocean-covered surface. There's also a potential signal of dimethyl sulphide (DMS), a molecule linked to microbial life on Earth, raising the prospect of biological activity on K2-18 b.
The findings from the research will be published in The Astrophysical Journal Letters and were presented on September 11, 2023, at the First Year of JWST Science Conference in Baltimore, Maryland, USA.
Sub-Neptunes like K2-18 b, with sizes between Earth and Neptune, have been a topic of discussion among the researchers due to the lack of similar planets in our Solar System. Lead author Professor Nikku Madhusudhan emphasizes the importance of considering diverse habitable environments in the search for extraterrestrial life, especially on Hycean worlds like K2-18 b, where atmospheric observations are more feasible.
The presence of methane and carbon dioxide, along with the potential for DMS, indicates the possibility of an ocean beneath a hydrogen-rich atmosphere on K2-18 b. However, the planet's large size, with a radius 2.6 times that of Earth, may contain a high-pressure ice mantle, making the habitability of its ocean uncertain. The abundance of sub-Neptunes in the galaxy makes understanding these planets crucial.
Further study of thw planets is to be done.