Dawn finale gives sharpest look ever at Ceres' bright spots

Thursday, 05 Jul, 2018

"Don is like a master artist, who is adding rich details to the beauty of the other world in his close picture of Ceres".

The northern wall of Occator Crater on Ceres.

Further scans of the dwarf planet could reveal more information about the surface and what lurks beneath.

Discovered by Dawn in 2015, when the spacecraft first reached Ceres, these mysterious faculae - including the largest one of them, Cerealia Facula, which resides at the heart of Occator Crater - are the biggest carbonate deposits ever uncovered outside our planet and might even be larger than those found on Mars.

NASA's Dawn mission flew at only 34 kilometers above Ceres on June 14th and 22nd, and, with these occasions, it caught the Occator Crater on camera again. This latest mission, the second one exploring the cosmic neighborhood of the dwarf planet, has brought Dawn within 22 miles (35 kilometers) from its surface.

After spending more than three years in the vicinity of Ceres, NASA's Dawn spacecraft shifted to a new orbit, one that brings the probe closer than ever to the dwarf planet and provides an unprecedented opportunity to observe and understand odd features seen on the distant body.

The close-up pictures should help Dawn's team answer follow-up questions relating to the origins of the bright spots. The new orbit allowed the spacecraft to get a sharper image of Ceres's weird bright spots at the Occator crater.

The plots at the bottom of craters Ceres was always in the shadows, researchers believe that there may be water ice, this theory was confirmed by the space station, which were able to detect deposits of the ice. Previous observations from the spacecraft's visible and infrared mapping spectrometer revealed that these deposits, featured in a pronounced depression, are made up from sodium carbonate.

In particular, scientists have been wondering how that material was exposed, either from a shallow, sub-surface reservoir of mineral-laden water, or from a deeper source of brines (liquid water enriched in salts) percolating upward through fractures.

"The first views of Ceres obtained by Dawn beckoned us with a single, blinding bright spot", she said. "Last week Dawn fired its ion engine, possibly for the final time", NASA said on a blog devoted to the space probe.

NASA engineer and Dawn project manager Marc Rayman, of the Jet Propulsion Laboratory, said the photos are the culmination of an incredible venture across the solar system.

Before its recent descent, the closest Dawn had traveled to Ceres was 240 miles (385 kilometers).

The other Dawn snapshot released by NASA on July 2 captures Cerealia Facula as it's never been seen before. Mission controllers look forward to continued science from Dawn, but they have completed all planned firing sessions of the industrious engines.