Biosignature Gases on K2-18b | 19 Apr 2025

Source: IE  

Researchers from the University of Cambridge have detected biosignature gases such as dimethyl sulphide (DMS) and dimethyl disulphide (DMDS) in the atmosphere of exoplanet K2-18b using the James Webb Space Telescope (JWST). 

• On Earth, these gases are mainly produced by biological processes, prompting debate about the possibility of extraterrestrial life. While the presence of DMS and DMDS is a strong potential biosignature, although not definitive evidence of life. 
  • Previous observations on planets like Mars and Venus have detected gases like phosphine, linked to life, but none provide conclusive evidence of life. 
• K2-18b: Discovered in 2015, it is a super-Earth exoplanet located 120 light years away. It has a mass 8.92 times that of Earth and orbits its M-type star every 32.9 days. The planet lies in the habitable zone and is 2.6 times the size of Earth. 
• JWST: It is the most advanced infrared space observatory ever built, launched in 2021 through the collaboration between NASA, the European Space Agency (ESA), and the Canadian Space Agency (CSA).  
  • It is positioned at the Sun-Earth L2 Lagrange Point.  As the successor to the Hubble Space Telescope, JWST is designed to look back to the universe’s earliest moments, just after the Big Bang.