Weird Bright Spots on Ceres Get a Close-Up from Dawn As Mission Nears End


This mosaic of a prominent mound on the floor of Ceres‘ Occator Crater was captured by NASA’s Dawn spacecraft on June 22, 2018, from an altitude of about 21 miles (34 kilometers). Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
NASA’s Dawn spacecraft has gotten its best-ever looks at the weird bright spots that speckle the dwarf planet Ceres.

By Mike Wall | SPACE.com

Early last month, Dawn maneuvered its way to a new orbit around Ceres, an elliptical path that takes the probe within a mere 21 miles (34 kilometers) of the dwarf planet on nearest approach. That’s more than 10 times closer than Dawn had gotten previously during its three-plus years at Ceres.

The views from this low altitude are amazing, as some newly released imagery of the 57-mile-wide (92 km) Occator Crater shows. [In Pictures: The Changing Bright Spots of Dwarf Planet Ceres]

Occator’s floor hosts odd bright deposits, which Dawn discovered during its approach to Ceres in early 2015. Subsequent observations by the probe revealed that the bright stuff, which also occurs at several other locations around Ceres, consists of sodium carbonate.

Scientists think this material was left behind when salty water boiled away into space. But it’s unclear where exactly that water came from. Was it concentrated in reservoirs near the surface? Or did it snake up to the surface via fissures from deep underground?

The newly released photos of Occator, which Dawn captured on June 14 and 22, could shed light on this mystery by painting a more complete picture of the crater floor, mission team members said.

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