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Sign life on K2-18b
Context
Scientists at the University of Cambridge, using data from NASA's James Webb Space Telescope (JWST), have detected potential biosignatures — molecules associated with life — in the atmosphere of exoplanet K2-18b, located 124 light years away. While not conclusive, this is the strongest signal yet in the search for extraterrestrial life.
What Did Scientists Detect?
- The James Webb Space Telescope (JWST) has detected traces of Dimethyl Sulphide (DMS) and Dimethyl Disulphide (DMDS) in the planet’s atmosphere.
- On Earth, DMS and DMDS are considered biosignatures — produced by simple life forms. If confirmed, this would be the first strong evidence of life beyond Earth.
- On Earth, these gases are only produced by living organisms, especially marine phytoplankton and bacteria.
- The detected quantity is thousands of times higher than levels on Earth—suggesting the possibility of abundant biological activity (if the source is life-related).
- How Was This Detected? Using infrared spectroscopy, JWST studied how the planet’s atmosphere absorbs starlight. This absorption pattern gives scientists clues about what chemicals are present in the atmosphere.
- Alternate Explanations: Gases could be produced through non-biological (abiotic) processes such as:
- Geological reactions.
- Molten oceans (not conducive to life).
- Mini gas giant structure with no solid surface.
What is K2-18b?
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