| Robert E. Johnson | | Professor, Materials Science and Engineering | | John Lloyd Newcomb Professor of Engineering Physics | | Ph.D., University of Wisconsin | | | | Johnson has served on the faculty since 1971. He has published over 200 papers, 12 review chapters, and two monographs and received an honorary doctorate from Uppsala University. He served as an assistant dean and now heads the graduate program in Engineering Physics and the undergraduate program in Engineering Science. | | | | Research Interests | | Johnson studies energetic ion, electron and photon interactions with surfaces and gases in space. His group develops the computational models necessary to describe the radiation-induced alterations of low-temperature ices and the collision cross-sections necessary to describe ion penetration of planetary atmospheres. The results are used to interpret spacecraft and telescope observations of planetary atmospheres, of grains in the interstellar medium, and of the effect of radiation on the moons of Jupiter and Saturn. Of particular interest are the moon Europa and the planet Mars. Europa has an underground ocean, and the incident radiation has been suggested as a source for biology. Mars has lost most of its atmosphere, a process that likely occurred after its magnetic field collapsed and the solar
wind plasma had access to the atmosphere. This group is now modeling the plasma effects occurring in Saturn's magnetosphere, in preparation for the arrival of the Cassini spacecraft in 2004. | | |
Sponsored Research
Erosion of Grains in the Interstellar Medium (funded by: NASA Headquarters)
Planetary Atmospheres (funded by: NASA Headquarters)
Irradiation of Ices in the Solar System (funded by: National Science Foundation)
Plasma Alteration of Surfaces in the Outer Solar System (funded by: NASA Headquarters)
Solar Wind Erosion of Mars Atmosphere (funded by: NASA Headquarters)
Cassini Mass Spectrometer: Modeling Studies (funded by: NASA Headquarters)
The OH Cloud in Saturn’s Magnetosphere (funded by: Virginia Space Grant Consortium)
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