JWST Finds Possible Biosignature Gases on Exoplanet K2-18b
Why in the news
Researchers from Cambridge have reported possible biosignature gases in the atmosphere of K2-18b, an exoplanet studied with the James Webb Space Telescope (JWST). The result is being described as among the strongest hints yet of life beyond the solar system, though it is not a confirmation.
Key facts
- Gases: dimethyl sulphide (DMS) and dimethyl disulphide (DMDS), which on Earth are typically made by marine microorganisms.
- Planet type: a super-Earth and a Hycean world, meaning water-rich with a hydrogen-dominated atmosphere.
- Caution: scientists stress that further observations are essential.
| K2-18b | Value |
|---|---|
| Distance | About 120 light-years |
| Discovered | 2015 |
| Mass | 8.92 times Earth |
| Size | 2.6 times Earth’s diameter |
| Orbital period | 32.9 days |
About JWST
JWST is the largest and most advanced infrared space observatory, built by NASA with the European Space Agency and the Canadian Space Agency. It was launched on 25 December 2021 and sits at the Sun-Earth L2 Lagrange point. It has 18 hexagonal gold-coated mirror segments and a large sunshield, and it studies the early universe.
Exam angle
- Gases to remember: DMS and DMDS.
- Planet: K2-18b, a Hycean super-Earth.
- Telescope: JWST, at L2, launched in 2021.
- Partners: NASA, ESA and CSA.