The origin of perennial water-ice at the South Pole of Mars
Thanks to data from ESA's Mars Express mission, combined with models of the
Martian climate, scientists can now suggest how the orbit of Mars around the Sun
affects the deposition of water ice at the Martian South Pole.
More at:
http://www.esa.int/esaSC/SEMKZRNSP3F_index_0.html