Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 29 May 1981:
Vol. 212. no. 4498, pp. 1027 - 1030
DOI: 10.1126/science.212.4498.1027
Prev | Table of Contents | Next

Articles

Erosion of Galilean Satellite Surfaces by Jovian Magnetosphere Particles

R. E. JOHNSON 1, L. J. LANZEROTTI 2, W. L. BROWN 2, and T. P. ARMSTRONG 3

1 Department of Nuclear Engineering and Engineering Physics, University of Virginia, Charlottesville 22901
2 Bell Laboratories, Murray Hill, New Jersey 07974
3 Department of Physics and Astronomy, University of Kansas, Lawrence 66045

The Galilean satellites of Jupiter—Io (J1), Europa (J2), Ganymede (J3), and Callisto (J4)—are embedded in the intense ion and electron fluxes of the Jovian magnetosphere. The effect of these particles on the icy surfaces of the outer three satellites depends on the fluxes and the efficiency of the sputtering of water ice by such particles. Recent laboratory measurements provided data on the erosion of water ice by energetic particles and showed that it occurs much faster than would be expected from normal sputtering theory. The Voyager spacecraft encounters with Jupiter provided the first measurements of ion fluxes (energies gsim 30 kiloelectron volts) in the vicinity of the Galilean satellites. Using the laboratory sputtering data together with particle measurements from the Voyager 1 low-energy charged particle experiment, the effects of erosion on the surfaces of J2 to J4 are estimated. It is shown that the surface of Europa could be eroded by as much as 100 meters over an eon (109 years). Column densities of water vapor that could be produced around the three satellites from particle bombardment of their surfaces are also calculated, and the sources and losses of oxygen in the gravitationally bound gas produced by sputtering or sublimation are estimated.

Submitted on September 16, 1980
Revised on January 19, 1981


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Fast Ion Bombardment of Ices and Its Astrophysical Implications.
W. L. Brown, L. J. Lanzerotti, and R. E. Johnson (1982)
Science 218, 525-531
   Abstract »    PDF »
Low-Energy Hot Plasma and Particles in Saturn's Magnetosphere.
S. M. KRIMIGIS, T. P. ARMSTRONG, W. I. AXFORD, C. O. BOSTROM, G. GLOECKLER, E. P. KEATH, L. J. LANZEROTTI, J. F. CARBARY, D. C. HAMILTON, and E. C. ROELOF (1982)
Science 215, 571-577
   Abstract »    PDF »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)