Evidence of biological activity outside the solar system can potentially change the way the night sky is fundamentally perceived, from seeing it as a physical, inanimate sky to thinking of it as a “living sky”, astrophysicist Nikku Madhusudhan has said.

A professor of astrophysics and exoplanetary science at the University of Cambridge, Madhusudhan is the lead researcher on a study that has found fingerprints of dimethyl sulphide and dimethyl disulphide molecules on an exoplanet—K2-18 b—about 120 light years from Earth. The molecules, known to be produced on Earth by marine organisms, are considered predictors of life or habitability on exoplanets. The results of the study are the strongest signs yet of life outside the solar system.