December 1st, 2012

Radar imaging of the north pole of Mercury on top of a mosaic of images taken by the Mercury Messenger spacecraft in the same area. All the large ice deposits in the polar region are located on the bottom or walls of impact craters. Deposits far from the pole appear to have been concentrated on the north-facing side of craters. Photo: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington/National Astronomy and Ionosphere Center, Arecibo Observatory

Ice marks on Mercury

Looking down Ilulissat Fjord towards its source, where the Jakobshavn Isbrae Glacier loses ice to Okiranus. The fjord is studded with glaciers along its entire length (60 kilometers). Photo by Ian Joughin, University of Washington

The Greenland and Antarctic ice sheets are losing ice rapidly