Context:
- Astrophysical Discovery: Using the James Webb Space Telescope (JWST), scientists have detected dimethyl sulfide (DMS) and dimethyl disulfide (DMDS) in the atmosphere of K2-18 b, a planet 120 light-years away in the constellation Leo.
- These gases are biosignatures on Earth, typically produced by marine phytoplankton and other microbial life.
Relevance : GS 3(Science and Technology)
Highlights:
Biosignature Detection:
- DMS and DMDS are only known to be produced biologically on Earth.
- Their detection in an exoplanet’s atmosphere marks a significant potential sign of extraterrestrial microbial life.
Nature of the Exoplanet – K2-18 b:
- Super-Earth: Mass is 8.6 times that of Earth, diameter is 2.6 times larger.
- Lies in the habitable zone of its star (where liquid water could exist).
- Considered a Hycean world – a class of planets with hydrogen-rich atmospheres and water-rich surfaces.
Scientific Caution:
- Researchers emphasize this is not a confirmation of life, but a possible biosignature.
- Further data and peer verification needed to rule out abiotic (non-living) sources of these gases.
Significance:
Breakthrough in Astrobiology:
- Marks a shift towards observational astrobiology — the study of life in the universe through direct observation of planets.
- Opens avenues for targeted searches for life on exoplanets with similar atmospheric chemistry.
Role of James Webb Space Telescope:
- JWST’s advanced spectroscopic capabilities allow chemical analysis of distant planetary atmospheres.
- Reinforces the technological leap in space observation.
Broader Implications:
- May influence future space exploration priorities.
- Could shape astroethics, interstellar communication policies, and planetary protection protocols.
