Ken Farley is the W.M. Keck Foundation Professor of Geochemistry in the Division of Geological and Planetary Sciences at the California Institute of Technology. His research centers on development and application of geochemistry techniques, especially involving isotopes of the noble gases, to a wide range of terrestrial and solar system questions. Specific areas of interest include geochronology of both Earth and Mars, the geochemical evolution of the Earth, and the behavior of noble gases in minerals. He began his professorial career at Caltech in 1993. Ken Williford has been a scientist at the Jet Propulsion Laboratory since 2012, and he serves as the Deputy Project Scientist for the Mars 2020 rover mission and the Director of the Astrobiogeochemistry Laboratory (abcLab). Ken is an astrobiologist specializing in organic and light isotope geochemistry, and his research is focused on understanding the formation, preservation and detection of signs of life and planetary evolution in geologic samples. Katie Stack has been a research scientist at the Jet Propsulsion Laboratory since 2014. She serves as the Deputy Project Scientist for the Mars 2020 Perseverance rover mission, and is a participating scientist for the Mars Science Laboratory Curiosity rover mission. Katie is a planetary geologist specializing in sedimentology, stratigraphy, and geologic mapping of planetary surfaces. Her research focuses on the Martian sedimentary rock record, using orbiter and rover image data to understand the evolution of ancient surface processes on Mars.