Mysterious Bright Spots on Ceres May Be 'Active Ice'

Tuesday, 17 March 2015 - 3:24PM
NASA
Astronomy
Tuesday, 17 March 2015 - 3:24PM
Mysterious Bright Spots on Ceres May Be 'Active Ice'
The "white spots" on Ceres have baffled scientists for months now, but new Dawn images may have finally solved the mystery. In a new study published in Nature, researchers theorize that the white spots are the result of an active geological feature made of ice.

Previous images from NASA's Dawn spacecraft revealed multiple white spots on Ceres of unknown origin, known as "feature number 5." Their nature is especially enigmatic because they appeared to be either depressions or mountains, depending on the angle of the image.

In the new images, they can be seen even when the pictures are taken near the edge of Ceres. As a result, they must rise relatively high above Ceres's surface, as usually the sides of the impact crater would hide anything at the bottom from Dawn's camera. 

"What is amazing is that you can see the feature while the rim is still in the line of sight," said Dawn team leader Andreas Nathues.

But the most revealing feature of the white spots is their tendency to fade over the course of the day. In the photos, they appear bright at dawn, but are much dimmer by the evening. This indicated that sunlight itself was a factor in feature number 5's appearance; the researchers hypothesize that the sun may warm up the ice just below the surface, causing it to rise and explode into a plume or a 'cryovolcano.'

"The big question is whether Ceres has an active region – or more than one," said Nathues.

This question, as well as many others about Ceres and its white spots, may be answered by the end of the Dawn mission. Near the end of the mission, the pictures will be at a high enough resolution that scientists will be able to discern features that are only 30 meters across, which will allow them to discover the true nature of feature number 5 with certainty.
Science
Space
NASA
Astronomy

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