BriefGlo

Scientists cannot visit distant exoplanets, but their atmospheres may contain clues to life. Here’s how biosignatures work and why they must be interpreted carefully.

Mars once had rivers and lakes. Now Perseverance has collected a rock sample containing potential biosignatures — but that is not yet proof of ancient life.

Enceladus sprays material from its hidden ocean directly into space. Cassini found water, organics, phosphorus and evidence of chemical energy — but has it found signs of life?

Europa may hide a vast saltwater ocean beneath its frozen surface. Here’s why scientists consider Jupiter’s icy moon one of the most promising places to investigate habitability beyond Earth.

From Mars and Europa to distant exoplanets, scientists are searching for biosignatures and technosignatures that could reveal life beyond Earth.