BellaOnline Forums Education Astronomy Dawn is in orbit around Ceres!

What has particularly had people wondering about Ceres even as Dawn was still approaching it? Easy. Those bright spots – what are they? There are more than 130 of them and most are associated with impact craters.

Since Ceres doesn't have a lander to take and analyze samples, researchers can't be certain about about what's there, but there is a lot of data that will help. One study has used this data to determine that the bright material is consistent with a substance called hexahydrite – it's similar to Epsom salt on Earth. They suggest that the salt was left behind when water-ice sublimated (turned from solid to vapor). Asteroid impacts would uncover the ice and salt mixture. The lead researcher says, "The global nature of Ceres' bright spots suggests that this world has a subsurface layer that contains briny water-ice."

Since mid-December Dawn has been in a Low Altitude Mapping Orbit (LAMO). The images that it's been taken will be of the highest resolution of the mission, because the spacecraft won't go any lower than this 385 km (240 miles) above Ceres.

This image is of Kupalo Crater, one of the youngest craters on Ceres. There is bright material exposed on the rim and wales, which could be salts like those in the bright spots in Occator Crater. The flat floor probably formed from impact melt and debris.

Kupalo Crater is named for the Slavic god of vegetation and harvest. Remember that http://www.bellaonline.com/articles/art2172.asp Ceres is named for a Roman goddess of the harvest.

(Photo Credits: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA)

There are new images released of Ceres taken when Dawn did its lowest-altitude mapping. This is the Haulani Crater. Its diameter is 34 km (21 mi). There seem to have been landslides from its rim. The central ridge also stands out clearly.

Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Dawn's mission ends on June 30, but what happens next? The Fate of NASA's Dawn Spacecraft Is Still Undecided.