1. Understanding Oxygen as an Exoplanet Biosignature

    Potential false positive mechanisms for O<sub>2</sub>. This cartoon summarizes the atmospheric mechanisms by which O<sub>2</sub> could form abiotically at high abundance in a planetary atmosphere (Meadows, 2017). Image credit: Ron Hasler
    Potential false positive mechanisms for O2. This cartoon summarizes the atmospheric mechanisms by which O2 could form abiotically at high abundance in a planetary atmosphere (Meadows, 2017).

    Researchers are studying how environmental context can help determine whether oxygen (O2) detected in extrasolar planetary observations is more likely to have a biological source. The team provide 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.

    Source: [Astrobiology]