NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Saturn Magnetospheric Impact on Surface Molecular Chemistry and Astrobiological Potential of EnceladusThe active south polar surface of Enceladus is exposed to strong chemical processing by direct interaction with charged plasma and energetic particles in the local magnetospheric environment of this icy moon. Chemical oxidation activity is suggested by detection of H202 at the surface in this region and less directly by substantial presence of C02, CO, and N2 in the plume gases. Molecular composition of the uppermost surface, including ejecta from plume activity, is radiolytically transformed mostly by penetrating energetic electrons with lesser effects from more depleted populations of energetic protons. The main sources of molecular plasma ions and E-ring dust grains in the magnetospheric environment are the cryovolcanic plume emissions from Enceladus. These molecular ions and the dust grains are chemically processed by magnetospheric interactions that further impact surface chemistry on return to Enceladus. For example, H20 neutrals dominating the emitted plume gas return to the surface mostly as H30+ ions after magnetospheric processing. Surface oxidant loading is further increased by return of radiolytically processed ice grains from the E-ring. Plume frost deposition and micrometeoroid gardening protect some fraction of newly produced molecular species from destruction by further irradiation. The evident horizontal and vertical mobility of surface ices in the south polar region drive mixing of these processed materials into the moon interior with potential impacts on deep ice molecular chemistry and plume gas production. Similarly as suggested previously for Europa, the externally driven source of radiolytic oxidants could affect evolution of life in any subsurface liquid water environments of Enceladus.
Document ID
20090006737
Acquisition Source
Goddard Space Flight Center
Document Type
Conference Paper
Authors
Cooper, Paul D.
(George Mason Univ. Fairfax, VA, United States)
Cooper, John F.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Sittler, Edward C.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Burger, Matthew H.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Sturner, Steven J.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Rymer, Abigail M.
(Johns Hopkins Univ. Laurel, MD, United States)
Date Acquired
August 24, 2013
Publication Date
December 13, 2008
Subject Category
Astrophysics
Meeting Information
Meeting: 2008 American Geophysical Union Meeting
Location: San Francisco, CA
Country: United States
Start Date: December 13, 2008
End Date: December 21, 2008
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available