Summer Evolution of the North Polar Cap of Mars as Observed by OMEGA/Mars Express

Y. Langevin (1) , F. Poulet (1) , J.-P. Bibring (1) , Bernard Schmitt (2) , Sylvain Douté (2) , B. Gondet (1)

1 IAS - Institut d'astrophysique spatiale
2 LPG - Laboratoire de Planétologie de Grenoble

The Observatoire pour la Mineralogie, l'Eau, les Glaces, et l'Activite (OMEGA) visible-infrared imaging spectrometer extensively observed regions of Mars with latitudes above 70[degrees]N in late 2004 (heliocentric longitude from Ls 93[degrees] to Ls 127[degrees]). The extent of water ice at the surface and the size of ice grains were monitored as a function of time. Bright, small-grained frost, which initially covered a large fraction of the polar cap, waned in favor of large-grained ice. In outlying regions, dominated by large-grained ice, the albedo increased over the period. Evaluating the dust content was model dependent. However, contamination of ice by dust was low.

Mots clés: ORBITER CAMERA; WATER ICE; MODEL; SURFACES

Y. Langevin, F. Poulet, J.-P. Bibring, Bernard Schmitt, Sylvain Douté, et al.. Summer Evolution of the North Polar Cap of Mars as Observed by OMEGA/Mars Express. Science, 2005, 307 (5715), pp.1581-1584. ⟨10.1126/science.1109438⟩. ⟨insu-00356297⟩