New Maps of Mercury Show Icy Looking Craters on the Solar System's Innermost Planet A NASA spacecraft bolsters the case that ice lines the inside of polar craters on Mercury (scientificamerican.com)
But some places on Mercury are slightly more stable.Inside polar craters on the diminutive planet are regions that never see the light of day, shaded as they are by the craters» rims. (scientificamerican.com)
MESSENGER's maps of polar craters match up nicely with earlier imagery of the poles, taken by Earth - based radars, which showed anomalously bright features — patches that reflected radio waves much better than the surrounding terrain, just as ice does. (scientificamerican.com)