Ken Farley is the W.M. Keck Foundation Professor of Geochemistry at the California Institute of Technology. His research centers around noble gas geochemistry and its applications to a range of Earth science problems. He is also interested in the exploration of Mars and its geochemistry, geology, and geomorphology; much of his current work is centered on Martian geochronology and surface exposure dating using in-situ noble-gas based techniques.
Biographical information and photo from Ken Farley's website.