Occator Crater on Ceres, as imaged by NASA’s Dawn spacecraft, features the brightest areas on the dwarf planet, evidence of past and possibly ongoing cryovolcanism. Image: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI
Close examination of data and imagery collected during NASA’s Dawn mission indicates the dwarf planet Ceres, the largest body in the asteroid belt, was geologically active with a unique form of cryovolcanism in the relatively recent past, researchers report in papers published by Nature Astronomy, Nature Geoscience and Nature Communications.
The research contradicts the long-held idea that small bodies, in the absence of heat-generating gravitational stresses, are not geologically active. To the contrary, Ceres may still be active today.
The conclusions are based on a detailed study of Occator Crater, a 92-kilometre-wide (57-mile-wide) impact structure that was blasted out some 22 million years ago. Occator generated widespread attention during Dawn’s approach to Ceres when long-range images showed two unusually bright, white features in the crater.
Based on high-resolution, close-range images captured later in Dawn’s mission, the researchers were able to characterise “a very complex structure with elevations, a large central depression, deposits, cracks and furrows,” said Andreas Nathues of the Max Plank Society and principal investigator of Dawn’s camera team.
“In all its ...