DAWN marks ice-bearing Ceres craters

Scientists with NASA’s Dawn mission have identified, on the dwarf planet Ceres, permanently shadowed regions most of which likely have been cold enough to trap water ice for a billion years. The findings suggest that that ice deposits could exist in these regions even now.

Key findings:

• The conditions on Ceres are right for accumulating deposits of water ice. Ceres has just enough mass to hold on to water molecules, and the permanently shadowed regions identified are extremely cold — colder than most that exist on the moon or Mercury.
• Permanently shadowed regions do not receive direct sunlight. They are typically located on the crater floor or along a section of the crater wall facing the pole. The regions still receive indirect sunlight, but if the temperature stays below about minus minus 151 degrees Celsius, the permanently shadowed area is a cold trap: a good place for water ice to accumulate and remain stable.

Dawn mission:

NASA’s Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. The mission will characterize the early solar system and the processes that dominated its formation.