Stephen M. CliffordStephen Clifford is a Senior Scientist at the Planetary Science Institute in Tucson, Arizona. He received his PhD in Astronomy from the University of Massachusetts in 1984. His research focuses on the nature, evolution and geophysical investigationof planetary volatiles, with a special emphasis on water on Mars. He is the author/co-author of 70 peer-reviewed publications whose topical focus has varied from investigations of H2O transport in cold planetary regoliths; large-scale groundwater transport; low-temperature hydrothermal convection in a sub-permafrost vadose zone; the formation and stability of gas hydrates; glacial flow and polar evolution; thermal modelling of planetary surfaces; the thermal, seismic and hydrologic effects of impact catering; and radar investigations of subsurface geology and the distribution and state of H2O. He was the principal convener of the 1st-4th International Conferences on Early Mars, 1st-5th International Conferences on Mars Polar Science and Exploration, and the Conference on the Geophysical Detection of Subsurface Water on Mars. Steve is the Deputy Science Team Leader for the WISDOM Ground Penetrating Radar which is part of the payload of ESA’s 2020 ExoMars Rover. He is also a U.S. Participating Scientist on the MARSIS orbital radar sounder on ESA’s Mars Express mission. Prior to joining the science staff at PSI in February 2018, Steve was a Senior Staff Scientist at the Lunar and Planetary Institute in Houston, Texas, where he conducted his Mars research for 34 years. Read More Read Less