HR: 1340h
AN: P23A-0243    [Abstracts]
TI: Potential Relation Between Caloris Basin And Mercury's Sodium Exosphere
AU: * Yan, N
EM: nicolas.yan@aerov.jussieu.fr
AF: Service dA\'eronomie, BP3, Verrieres-le-Buisson, 91371 France
AU: Leblanc, F
EM: francois.leblanc@aerov.jussieu.fr
AF: Service dA\'eronomie, BP3, Verrieres-le-Buisson, 91371 France
AU: Chassefi\`ere, E
EM: Eric.Chassefiere@aero.jussieu.fr
AF: Service dA\'eronomie, BP3, Verrieres-le-Buisson, 91371 France
AB: A Mercury's thermal model has been developed, in order to describe theorically the temperature of the surface exposed to solar radiation. This model describes the surface temperature and the first meters below during a whole diurnal cycle. Such a model has been tested with respect to known measurements of Mercury's surface temperature (Chase et al. 1976) and previous models (Hapke and Hale 2002). This model has been coupled to 3-D Monte Carlo model of Mercury's sodium exosphere (Leblanc et al. 2003). This last model describes the sodium adsorption/desorption cycle during a whole diurnal period and has been compared successfully to observations. We here use the thermal model to describe in details the temperature variation induced by the slope associated to Caloris Basin. The results on the sodium exosphere with respect to Mercury positions around the Sun will be described and will discuss the potential role of the particular topography of Mercury's Caloris basin, especially in comparison with exospheric sodium emissions observations (Potter et al.) which revealed North/South hemispheric asymmetries. References: Chase et al. Icarus, 28:655, 1976 - Hale and Hapke, Icarus, 156, 318, 2002 - Leblanc et al., J. Geophys. Res., 108, E12, 5136, 2003 - Potter et al., Plan. Space Sci., 47, 1441, 1999.
DE: 6235 Mercury
SC: Planetary Sciences [P]
MN: 2004 AGU Fall Meeting