NASA’s Dawn spacecraft is now in its second mapping orbit around the dwarf planet Ceres. At just 2,700 miles above Ceres, today’s images are the sharpest yet.
Ceres’ bright white spots took center stage again. Look at how many small white spots are inside the crater in the image below.
Scientists still aren’t sure what the bright white spots are, but ice remains the leading candidate. Chris Russell, principal investigator for the Dawn mission, says the Dawn team is considering other explanations for the bright spots including salt.
“The bright spots in this configuration make Ceres unique from anything we’ve seen before in the solar system,” said Russell.
Ceres isn’t just a group of bright spots. Scientists are also seeing evidence of increased surface activity such as landslides and collapsed structures.
Ceres captured several images of Ceres’ cratered surface on June 6th.
This image shows a large crater in Ceres’ southern hemisphere surrounded by many smaller ones.
The northern hemisphere is scarred by hundreds of craters ranging in size.
This image was snapped with Dawn’s visible and infrared mapping spectrometer (VIR). Man, I wish the Dawn team snapped an image of the bright white spots with it. The bottom image slice is a temperature image using data in the infrared light range. The VIR should come in handy as scientists figure out exactly what the bright white spots are.
Ceres’ bright spots are probably ice, and that makes it even more intriguing
Let’s assume Ceres’ bright spots are ice. What does it mean? It could be a variety of things. Maybe there is some kind of volcanism at play. Ice geysers are another possibility. But, both would raise questions about Ceres’ thermodynamics.
A meteor impact could also have exposed the ice. Could there be more ice under Ceres’ surface?
Right now, the question is what are the bright spots? Answering that will only bring about more questions.
The Dawn team hopes to have a more definitive answer about the bright spots as the spacecraft gets closer and closer to Ceres.
What does the future hold for Dawn?
The spacecraft is currently in its second mapping orbit, called a survey science orbit. This is expected to last until June 30. In July, Dawn will start descending even closer towards Ceres. By August 4, it will be 910 miles above the dwarf planet as it enters a high-altitude mapping orbit.
Later this year, Dawn will be even closer to Ceres. The spacecraft will be just 230 miles above Ceres on December 15.
It will be interesting to see if these bright spots change any as Dawn orbits Ceres over the next 12 months.
NASA also released a new animated video this week of Ceres.
“We used a three-dimensional terrain model that we had produced based on the images acquired so far,” said Dawn team member Ralf Jaumann of the German Aerospace Center (DLR), in Berlin. “They will become increasingly detailed as the mission progresses — with each additional orbit bringing us closer to the surface.”
Image credits: NASA/JPL