Scientists are pretty sure that Ceres, the dwarf planet between Mars and Jupiter, holds water. But a new paper out this week suggests that it might contain more than liquid H2O: A portion of its surface, particularly near the poles, could be coated in a thin layer of ice. Studying how it built up there will help researchers understand how ice forms all over our solar system. T.H. Prettyman and N. Yamashita, Planetary Science Institute
