The role of sputtering and radiolysis in the generation of Europa exosphere

Details The role of sputtering and radiolysis in the generation of Europa exosphere The role of sputtering and radiolysis in the generation of Europa exosphere

Apr 2012

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012icar..218..956p&link_type=abstract

Icarus, Volume 218, Issue 2, p. 956-966.

Computer Science

Scientific paper

The exosphere of an atmosphereless icy moon is the result of different surface release processes and subsequent modification of the released particles. At Europa icy moon, water molecules are directly released, but photolysis and radiolysis due to solar UV and Jupiter's magnetospheric plasma, respectively, can result in OH, H, O and (possibly) H2 production. These molecules can recombine to reform water and/or new chemical species. As a consequence, Europa's neutral environment becomes a mixture of different molecules, among which, H2O dominates in the highest altitudes and O2, formed mainly by radiolysis of ice and subsequent release of the produced molecules, prevails at lower altitudes. In this work, starting from a previously developed Monte Carlo model for the generation of Europa's exosphere, where the only considered species was water, we make a first attempt to simulate also the H2 and O2 components of the neutral environment around Europa, already observed by the Hubble Space Telescope and the Ultraviolet Imaging Spectrograph on board Cassini, during its flyby of Jupiter. Considering a specific configuration where the leading hemisphere coincides with the sunlit hemisphere, we estimate along the Europa–Sun line an O2 column density of about 1.5 × 1019 m‑2 at the dayside and 3 × 1018 m‑2 at the nightside. In this work we also improve our previous estimation of the sputtered H2O exosphere of this moon, taking into consideration the trailing–leading asymmetry in the magnetospheric ion bombardment and the energy and temperature dependences of the process yields. We find that a density of 1.5 × 1012 H2O/m3 is expected at altitudes ˜0.1RE above the surface of the trailing hemisphere. Additionally, we calculate the escape of H2O, O2 and H2. The total number of neutral atoms in Europa's neutral torus, is estimated to be in the range 7.8 × 1032–3.3 × 1033.

Affiliated with

Also associated with

No associations

Rating

The role of sputtering and radiolysis in the generation of Europa exosphere does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The role of sputtering and radiolysis in the generation of Europa exosphere, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The role of sputtering and radiolysis in the generation of Europa exosphere will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1118059