Discovery of Dimethyl Sulphide on Exoplanet K2-18b
The detection of dimethyl sulphide (DMS), a volatile sulphur compound that gives the sea its distinctive odor, has been suggested as a potential biosignature for life. This compound is produced by algae blooms near the sea surface and is indicative of the possibility of life.
Findings on K2-18b
- A recent study in the Astrophysical Journal Letters highlighted an abundance of DMS on K2-18b, a planet orbiting a star 124 light years away from Earth.
- The concentrations of DMS on K2-18b are reportedly thousands of times stronger than those on Earth.
- The study utilized data from the James Webb Telescope to support these findings.
Implications for Astrobiology
- K2-18b, discovered in 2015 by NASA's Kepler mission, is a sub-Neptune located in the "Goldilocks Zone" of a star, which is conducive to containing water and potentially life.
- The challenge in studying such planets is that their parent stars often outshine them, making atmospheric studies difficult.
- Madhusudhan's team bypassed this issue by analyzing the light passing through K2-18b's atmosphere during its transit.
- Previous studies in 2023 identified methane and carbon dioxide in K2-18b’s atmosphere, with a hint of DMS, but the recent study confirms a stronger presence of the gas.
Future Research and Challenges
- Further studies are necessary to understand if DMS behaves similarly on K2-18b as it does on Earth.
- The search for extraterrestrial life has gained momentum with the James Webb Telescope, capable of analyzing planetary atmospheres through starlight.
- Currently, this telescope can only detect larger, distant planets like K2-18b.
- NASA aims to develop an observatory to detect atmospheres of smaller, Earth-sized distant planets, although funding challenges may delay progress.