DC Edit | Life On An Exoplanet?

The discovery of two chemicals on an exoplanet 124 light years (1,173 lakh crore kilometres) away from Earth is a Eureka moment for the scientific community. The excitement stems from the fact that these chemicals — dimethyl sulfide (DMS) and dimethyl disulfide (DMDS) — are only produced by life forms such as marine algae and other microbes on Earth, and by extension, their presence would hint at the possible existence of life on another planet.

The six researchers from the University of Cambridge, who include three with roots in India, detected the molecules by analysing the images of starlight sent to Earth by the James Webb Space Telescope. As different chemical compounds emit distinct imprints in the light’s spectrum, the researchers study images of exoplanets for new signals. In 2023, the same researchers detected methane and carbon dioxide in the same planet's atmosphere.

The exoplanet — named K2-18b — appears to have most of the ingredients which are required for the evolution of life. It orbits its star in the region — which is not extremely hot or extremely cold — where liquid water can exist on a planet's surface. It is 2.6 times the size of Earth and 8.6 times its mass, both of which is important in terms of gravity.

The Cambridge researchers claim a 0.3 per cent probability that the finding occurred by chance. Sceptics, however, argue that it could be a spurious signal.

Theoretically, these two chemicals could be produced without the presence of life. Nevertheless, the presence of these chemicals give a faint hope that we — life forms that evolved on the earth — are not alone in the universe. If even a trace of credible evidence emerges pointing to extraterrestrial life, it would completely redefine our understanding of biology, evolution and the place of terrestrial life forms in the cosmos. The quest for the unknown, therefore, must continue.