Tanja Bosak is professor of geobiology in the Department of Earth, Atmospheric and Planetary Sciences at MIT and the group leader of the Program in Geology, Geochemistry and Geobiology. Bosak’s work in experimental geobiology asks how microbial processes leave chemical, mineral, and morphological signals in sedimentary rocks. The research in her lab combines microbiology, materials science and sedimentology to explore modern biogeochemical and sedimentological processes, interpret the coevolution of life and the environment during the first 80% of Earth’s history, and search for signs of past life or prebiotic processes on Mars. Bosak’s awards include the 2007 Subaru Outstanding Woman in Science Award from the Geological Society of America and the 2011 James B. Macelwane Medal from the American Geophysical Union. Bosak is an American Geophysical Union Fellow and a member of NASA’s Mars 2020 Project Science Group. Born in Croatia, Bosak earned a BS in geophysics from Zagreb University and a PhD in geobiology from the California Institute of Technology.