New Telescopes Aim to Decode Alien Atmospheres in Search of Life

Astronomers are developing precise methods to detect alien life by decoding chemical signatures in distant planetary atmospheres. Current techniques rely on analyzing molecular 'barcodes' imprinted on starlight as exoplanets transit their host stars.

While the James Webb Space Telescope (JWST) has successfully detected methane, carbon dioxide, and water vapor in exoplanet atmospheres, these observations remain limited by the need for transits and the faintness of atmospheric signals.

The 2025 claim of dimethyl sulphide detection in the atmosphere of K2-18b—a molecule associated with life on Earth—has since been challenged by researchers at Arizona State University.

'The spectral features attributed to dimethyl sulphide could be explained by other compounds or instrumental noise,' said the team in a Nature Astronomy analysis. This highlights the need for independent verification and larger telescopes to resolve such ambiguities.

Upcoming missions aim to address these limitations. ESA's Plato (2026) will focus on identifying Earth-sized planets in habitable zones, while NASA's Roman (2029) and ESA's Ariel (2029) will analyze atmospheric compositions with improved precision.

NASA's Habitable Worlds Observatory (HWO), currently in development, will search for oxygen, the vegetation red edge, and surface features through reflected light analysis. These instruments will operate with enhanced sensitivity but will still require years of data collection to confirm biosignatures.