Dr. Jeffrey R. Johnson is a Principal Professional Scientist at the Johns Hopkins University Applied Physics Laboratory. His background is in visible/near-infrared spectroscopy, radar imaging and surface properties of Venus, thermal infrared imaging and spectroscopy of terrestrial materials, light scattering properties and radiative transfer modeling applied to the Moon and Mars, and spectral studies of shocked minerals and rocks. He has participated in several Mars lander/rover spacecraft missions, studying visible/near-infrared spectroscopy and surface morphology. He was an Associate Principal Investigator and Participating Scientist for the Mars Exploration Rover Opportunity, is currently a Participating Scientist on the Mars Science Laboratory Curiosity, and a Co-Investigator on the SuperCam and Mastcam-Z instruments on the Mars2020 rover mission. He also serves as the Chair of the Mars Exploration Program Analysis Group (MEPAG) and is an Associate Editor for Icarus.