Roger Jay Phillips (June 9, 1940 – November 19, 2020) was an American geophysicist,

planetary scientist Planetary science (or more rarely, planetology) is the scientific study of planets (including Earth), celestial bodies (such as moons, asteroids, comets) and planetary systems (in particular those of the Solar System) and the processes of their ...

, and professor emeritus at the

Washington University in St. Louis Washington University in St. Louis (WashU) is a private research university in St. Louis, Missouri, United States. Founded in 1853 by a group of civic leaders and named for George Washington, the university spans 355 acres across its Danforth ...

. His research interests included the geophysical structure of planets, and the use of

radar Radar is a system that uses radio waves to determine the distance ('' ranging''), direction ( azimuth and elevation angles), and radial velocity of objects relative to the site. It is a radiodetermination method used to detect and track ...

and gravity to investigate the surfaces and interiors of the planets.

Career

Roger J. Phillips received his Ph.D. in 1968 from the

University of California, Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California), is a Public university, public Land-grant university, land-grant research university in Berkeley, California, United States. Founded in 1868 and named after t ...

where he studied with Stan Ward. Following graduate school he worked at the

Jet Propulsion Laboratory The Jet Propulsion Laboratory (JPL) is a Federally funded research and development centers, federally funded research and development center (FFRDC) in La Cañada Flintridge, California, Crescenta Valley, United States. Founded in 1936 by Cali ...

. His work at JPL included being the team leader for the

Apollo 17 Apollo 17 (December 7–19, 1972) was the eleventh and final mission of NASA's Apollo program, the sixth and most recent time humans have set foot on the Moon. Commander Gene Cernan and Lunar Module Pilot Harrison Schmitt walked on the Moon, ...

Lunar Sounder Experiment (ALSE). Phillips then served as the Director of the

Lunar and Planetary Institute The Lunar and Planetary Institute (LPI) is a scientific research institute dedicated to study of the Solar System, its formation, evolution, and current state. The Institute is part of the Universities Space Research Association (USRA) and is ...

before moving to

Southern Methodist University Southern Methodist University (SMU) is a Private university, private research university in Dallas, Texas, United States, with a satellite campus in Taos County, New Mexico. SMU was founded on April 17, 1911, by the Methodist Episcopal Church, ...

, and later to

where he served as a Professor and as Director of the McDonnell Center for the Space Sciences at the university. Phillips worked on several spacecraft missions such as

Magellan Ferdinand Magellan ( – 27 April 1521) was a Portuguese people, Portuguese explorer best known for having planned and led the Magellan expedition, 1519–22 Spanish expedition to the East Indies. During this expedition, he also discovered t ...

Mars Global Surveyor ''Mars Global Surveyor'' (MGS) was an American Robotic spacecraft, robotic space probe developed by NASA's Jet Propulsion Laboratory. It launched November 1996 and collected data from 1997 to 2006. MGS was a global mapping mission that examined ...

Mars Reconnaissance Orbiter The ''Mars Reconnaissance Orbiter'' (''MRO'') is a spacecraft designed to search for the existence of water on Mars and provide support for missions to Mars, as part of NASA's Mars Exploration Program. It was launched from Cape Canaveral on Au ...

, and

MESSENGER Messenger, Messengers, The Messenger or The Messengers may refer to: People * Courier, a person or company that delivers messages, packages, or mail * Messenger (surname) * Bicycle messenger, a bicyclist who transports packages through cities * M ...

. Phillips served as the editor of ''

Geophysical Research Letters ''Geophysical Research Letters'' is a biweekly peer-reviewed scientific journal of geoscience published by the American Geophysical Union that was established in 1974. The editor-in-chief iKristopher Karnauskas Aims and scope The journal aims for ...

'' and co-edited the books the ''Origin of the Moon'' and ''Venus II''. Phillips was a fellow of the

American Geophysical Union The American Geophysical Union (AGU) is a 501(c)(3) nonprofit organization of Earth, Atmospheric science, atmospheric, Oceanography, ocean, Hydrology, hydrologic, Astronomy, space, and Planetary science, planetary scientists and enthusiasts that ...

, received the

G. K. Gilbert Award The G. K. Gilbert Award is presented annually by the Planetary Geology Division of the Geological Society of America for outstanding contributions to the solution of fundamental problems in planetary geology in the broadest sense, which includes ge ...

from the

Geological Society of America The Geological Society of America (GSA) is a nonprofit organization dedicated to the advancement of the geosciences. History The society was founded in Ithaca, New York, in 1888 by Alexander Winchell, John J. Stevenson, Charles H. Hi ...

in 2003 and the

Whipple Award The Fred Whipple Award, established in 1989 by the Planetary Sciences Section of the American Geophysical Union, is presented to an individual who makes an outstanding contribution to the field of planetary science. The award was established to ho ...

from the

in 2008

Scientific contributions

Phillips' early work determined that the mascons on the Moon that perturbed the trajectory of early lunar orbiters was the result of near surface structure of impact basins and made some of the early estimates of the thickness of the crust of Mars prior to the Viking orbiters. Using the Apollo 17 Lunar Sounder Experiment data Phillips and his team collected they made the first observations of near surface variations in rock layers on the Moon. Phillips is well-known for his contributions to understanding the tectonics, impact craters and resurfacing history and the interior and crustal evolution of Venus. Phillips is also known for explaining how the growth of the massive

Tharsis Tharsis () is a vast volcanic plateau centered near the equator in the western hemisphere of Mars. The region is home to the largest volcanoes in the Solar System, including the three enormous shield volcanoes Arsia Mons, Pavonis Mons, and A ...

volcanic province on Mars shaped the entire planet and influenced the pattern of precipitation runoff on early Mars and demonstrating how the

lithosphere A lithosphere () is the rigid, outermost rocky shell of a terrestrial planet or natural satellite. On Earth, it is composed of the crust and the lithospheric mantle, the topmost portion of the upper mantle that behaves elastically on time ...

of Mars under the north pole of the planet is not deflected by the massive polar caps. He also demonstrated that there are CO₂ ice deposits within the southern polar cap of Mars.

References

{{DEFAULTSORT:Phillips, Roger J. Fellows of the American Geophysical Union American planetary scientists American geophysicists University of California, Berkeley alumni Colorado School of Mines alumni Washington University in St. Louis faculty 1940 births 2020 deaths American academic journal editors Scientists from Missouri Lunar and Planetary Institute