"Surface and Atmospheric Biosignatures in the Era of the ELTs and HWO"

Independent lines of evidence will be required to support the detection of life beyond Earth. Adding to current methods, missions such as the Extremely Large Telescopes (ELTs) and the Habitable World Observatory (HWO) will observe terrestrial exoplanets in reflected light. In this talk, I present the opportunity for surface and cloud biosignatures to act as complementary signatures of life to atmospheric biosignatures, integrating laboratory spectroscopy, field studies of extreme environments, and reflectance spectrum modeling. I focus on how biological pigments, microbial surface communities, and atmospheric microorganisms change planetary albedos and observability. Using polar and high-altitude analog environments on Earth, I explore how Earth’s biosignatures can help strengthen the interpretation of biosignature detections on a wider scale. This work provides a framework for incorporating surface and cloud biosignatures into reflected-light observations, informing strategies for the ELTs, HWO, and other life-detection missions.