HR: 0800h
AN: P51D-0954    [Abstracts]
TI: Characterization of the Radiation on the Surface of Mars and its Astrobiological Implications
AU: * Schneider, S I
EM: sschneid@geosc.psu.edu
AF: Pennsylvania State University, Deike 439, Univerxsity Park, pa 16802 United States
AB: Little is known about the radiation environment on the surface of Mars due to the fact that no lander/probe has carried out in-situ nuclear radiation measurements. The first mission set to accomplish this task, the Mars Science Laboratory or MSL, is not due to launch until 2009. So far, only incoming cosmic radiation and solar particle events had been considered, while the scattered nuclear radiation contribution was usually neglected or ignored. Recent detection by the Mars Odyssey orbiter of subsurface hydrogen on Mars, by means of the direct detection of neutrons and gamma rays, has prompted an in depth study of this backscattered contribution. Simulations using specialized nuclear transport codes such as NASA's HZETRN code, have shown that this contribution might in fact be quite significant, and thus that it must be accounted for. Presented here are some preliminary estimates for these nuclear radiation doses as delivered by thermal, epithermal and fast neutrons which arise from nuclear interactions of incident cosmic rays with the martian atmosphere and the martian regolith. Implications for terrestrial planet habitability will be discussed.
DE: 0315 Biosphere/atmosphere interactions (0426, 1610)
DE: 0360 Radiation: transmission and scattering
DE: 2104 Cosmic rays
DE: 2114 Energetic particles (7514)
DE: 6225 Mars
SC: Planetary Sciences [P]
MN: Fall Meeting 2005