Cassini finds an oxygen-carbon dioxide atmosphere at Saturn's icy moon Rhea
Teolis, B.D. and Jones, Geraint H. and Miles, P.F. and Tokar, R.L. and Magee, B.A. and Waite, J.H. and Roussos, E. and Young, D.T. and Crary, F.J. and Coates, Andrew J. and Johnson, R.E. and Tseng, W.L. and Baragiola, R.A. (2010) Cassini finds an oxygen-carbon dioxide atmosphere at Saturn's icy moon Rhea. Science 24 , pp. 1813-1815. ISSN 0036-8075.
The flyby measurements of the Cassini spacecraft at Saturn's moon Rhea reveal a tenuous oxygen (O-2)-carbon dioxide (CO2) atmosphere. The atmosphere appears to be sustained by chemical decomposition of the surface water ice under irradiation from Saturn's magnetospheric plasma. This in situ detection of an oxidizing atmosphere is consistent with remote observations of other icy bodies, such as Jupiter's moons Europa and Ganymede, and suggestive of a reservoir of radiolytic O-2 locked within Rhea's ice. The presence of CO2 suggests radiolysis reactions between surface oxidants and organics or sputtering and/or outgassing of CO2 endogenic to Rhea's ice. Observations of outflowing positive and negative ions give evidence for pickup ionization as a major atmospheric loss mechanism.
|School:||Birkbeck Schools and Departments > School of Science > Earth and Planetary Sciences > UCL/Birkbeck Centre for Planetary Sciences|
|Date Deposited:||14 Jun 2011 07:59|
|Last Modified:||17 Apr 2013 12:20|
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