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

摘要

The Observatoire pour la Mineralogie, l'Eau, les Claces, et l'Activite (OMEGA) visible-infrared imaging spectrometer extensively observed regions of Mars with latitudes above 70°N in late 2004 (heliocentric longitude from L_s 93° to L_s 127°). 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.