Quirks & Quarks

Dwarf Planet Ceres Shows Some Bright Spots

NASA's Dawn spacecraft has observed the long-mysterious bright spots on the dwarf planet Ceres in the Asteroid Belt and scientists say they're signs of water welling up from under the outer crust.

Bright spots on Ceres in the Asteroid belt could indicate sub-surface water

Enhanced false colour image of Ceres' Occator Crater with bright deposits in its bowl. (NASA/JPL-Caltech/UCLA/MPS/DLR/IDA)
The dwarf planet Ceres is the largest object in the asteroid belt between Mars and Jupiter, with a diameter of about 1000km. Scientists have long been puzzled by bright spots on the surface of Ceres, but until NASA's Dawn mission arrived in orbit around it last April, they haven't been able to see enough detail to understand what they were.

Now, images have revealed that these spots most frequently appear at the bottom of impact craters, and this, as well as imaging, has revealed what they might be. According to Dr. Ed Cloutis, from the Department of Geography at the University of Winnipeg, and his colleagues, these are deposits of salt, which are likely carried up from a briny layer of water/ice below the surface when an impact punches through the surface crust.

Researchers were able to observe a "haze" of evaporating water above the salt deposits, suggesting this process continues to be active on Ceres today.

Related Links

Paper in Nature
- NASA JPL release
Nature News story
- Scientific American article
- CBC News story