Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published January 1977 | public
Journal Article

Stability of an oxygen atmosphere on Ganymede

Abstract

Photolysis of water and subsequent escape of hydrogen can give rise to an oxygen atmosphere on Ganymede. Growth of the atmosphere may be limited by escape of fast oxygen atoms formed by photodissociation of O_2. Escape of oxygen and hydrogen in an equilibrium configuration should balance net evaporation of water from the satellite's surface and the partial pressure of atmospheric O_2 could be as high as 10^(−3) mbar. Ganymede should have lost an appreciable quantity of water over geologic time, enough to have coated the surface of the satellite with ice to a depth of about 2 m. An oxygen atmosphere with similar properties might be expected to occur also on Callisto.

Additional Information

Copyright © 1977 Published by Elsevier Inc. Received September 14, 1976. We are indebted to D. L. Matson, who provided a thermal model used here to estimate the mean value for the surface pressure of water vapor on Ganymede. This research was supported by the Atmospheric Sciences Section of the National Science Foundation under Contract NSF-ATM-75-22723, and by AURA Contract 802-73, both to Harvard University.

Additional details

Created:
August 22, 2023
Modified:
October 17, 2023