Data from NASA’s GRACE satellite (Gravity Recovery and Climate Experiment) has been used to show that the East Antarctic ice sheet is losing mass. GRACE has previously shown that the smaller West Antarctic and Greenland ice sheets are losing mass, but it was thought the East Antarctic was stable.
The data suggests there was no net loss between 2002 and 2006, but has been losing mass over the last three years. Whilst the loss is small compared to the West Antarctic Ice Sheet, it is a surprising find. More reporting is available here or best read the paper published in Nature Geoscience (Accelerated Antarctic ice loss from satellite gravity measurements, Chen J.L. et al, Nature Geoscience, 2009).