COSMOS-LIVE.COM

Site about space and the universe

Мкс Онлайн
ISS ONLINE
Space Online
HEADER 1
NASA TV
[wpmegamenu menu_location="top"]

What Are the Bright Spots on Ceres?

What Are the Bright Spots on Ceres?

image

Dwarf planet Ceres has more than 130 bright areas, and most of them are associated with impact craters. Now, Ceres has revealed some of its well-kept secrets in two new studies in the journal Nature, thanks to data from our Dawn spacecraft.

Two studies have been looking into the mystery behind these bright areas. One study identifies this bright material as a kind of salt, while the other study suggests the detection of ammonia-rich clays. 

Study authors write that the bright material is consistent with a type of magnesium sulfate called hexahydrite. A different type of magnesium sulfate is familiar on Earth as Epsom salt.

image

Researchers, using images from Dawn’s framing camera, suggest that these salt-rich areas were left behind when water-ice sublimated in the past. Impacts from asteroids would have unearthed the mixture of ice and salt.

An image of Occator Crater (below) shows the brightest material on Ceres. Occator itself is 60 miles in diameter, and its central pit, covered by this bright material, measures about 6 miles wide. With its sharp rim and walls, it appears to be among the youngest features on the dwarf planet.

image

In the second nature study, members of the Dawn science team examined the composition of Ceres and found evidence for ammonia-rich clays. Why is this important?

Well, ammonia ice by itself would evaporate on Ceres today, because it is too warm. However, ammonia molecules could be stable if present in combination with other minerals. This raises the possibility that Ceres did not originate in the main asteroid belt between Mars and Jupiter, where it currently resides. But instead, might have formed in the outer solar system! Another idea is that Ceres formed close to its present position, incorporating materials that drifted in from the outer solar system, near the orbit of Neptune, where nitrogen ices are thermally stable.

image

As of this week, our Dawn spacecraft has reached its final orbital altitude at Ceres (about 240 miles from the surface). In mid-December, it will begin taking observations from this orbit, so be sure to check back for details!

ake sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

Leave a Reply

Your email address will not be published. Required fields are marked *