Researchers are studying how environmental context can help determine whether oxygen (O2) detected in extrasolar planetary observations is likely to have a biological source. The team provides an in-depth, interdisciplinary example of O2 biosignature identification and observation, which serves as the prototype for the development of a general framework for biosignature assessment.

The article, “Exoplanet Biosignatures: Understanding Oxygen as a Biosignature in the Context of Its Environment,” is an open access article in the journal Astrobiology. The work was supported by the NASA Astrobiology Program and in part by the NASA Astrobiology Institute’s Virtual Planetary Laboratory and Alternative Earths Teams.