Weekly Current Affairs

DAWN marks ice-bearing Ceres craters [S&T]

  • 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 ice deposits could exist in these regions even now.
  • Ceres has just enough mass to hold on to water molecules, and the permanently shadowed regions we 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 crater floor or along a section of 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.
  • Some observations indicate Ceres may be a volatile-rich world that is not dependent on current-day external sources.
  • The researchers found dozens of sizeable permanently shadowed regions across the northern hemisphere.