Joshua Krissansen-Totton is a planetary scientist and astrobiologist who specializes in modeling the biogeochemical evolution of rocky planets, including interactions between atmospheres, surfaces, and interiors. His research spans the early Earth, Venus, and newly discovered rocky exoplanets. Krissansen-Totton combines Earth system science, namely models of carbon and oxygen cycling in deep time, with an awareness of astronomical observations to formulate testable hypotheses about terrestrial planet atmospheres and support the search for life beyond Earth.