Figure iii: A sea of molecules fills chemical space, as shown in the distance. A subset of choice molecules makes it through the shaker filter into three different streams. Two of the streams include molecules produced by life on Earth and reach near an exoplanet, illustrating the hope that some of these molecules are relevant for the search for life on other worlds. The paper represented by the journal cover “Toward a List of Molecules as Potential Biosignature Gases for the Search for Life on Exoplanets and Applications to Terrestrial Biochemistry” presents a new approach to the subject of biosignature gases (gases in an exoplanet atmosphere produced by life that accumulate to levels detectable by a space telescope). Since one cannot predict which molecules might be produced by life on other worlds, my research involves a list of all molecules (over 14,000) that are likely volatile and stable on habitable-zone planets. The goal is to use the list to study classes of chemicals that might be potential biosignature gases, considering their accumulation and possible false positives on exoplanets different from Earth. (Image: Joanna Petkowska)
