Bright Areas on Ceres Suggest Geologic Activity

The surface of the dwarf planet Ceres is generally looking quite dark, but with notable exceptions. NASA’s Dawn spacecraft sent back images of hundreds of bright areas that stand out there.

Now, scientists have a better sense of how these reflective areas formed and changed over time – processes indicative of an active, evolving world.

“The mysterious bright spots on Ceres, which have captivated both the Dawn science team and the public, reveal evidence of Ceres’ past subsurface ocean, and indicate that, far from being a dead world, Ceres is surprisingly active. Geological processes created these bright areas and may still be changing the face of Ceres today,” said Carol Raymond, deputy principal investigator of the Dawn mission, based at NASA’s Jet Propulsion Laboratory in Pasadena, California.

Raymond and colleagues presented the latest results about the bright areas at the American Geophysical Union meeting in New Orleans on Tuesday, Dec. 12.

Scientists have located more than 300 bright areas on Ceres since Dawn arrived in orbit at Ceres in March 2015

Different Kinds of Bright Areas

A new study in the journal Icarus, led by Nathan Stein, a doctoral researcher at Caltech in Pasadena, California, divides Ceres’ features into four categories.

Found on crater floors, the first group of bright spots contains the most reflective material on Ceres.

Occator Crater hosts two prominent bright areas. Cerealia Facula consists of bright material covering a 10-kilometer-wide (6-mile-wide) pit, within which sits a small dome and Vinalia Faculae, situated east of the center, is a collection of slightly less reflective and more diffuse features.

All the bright material in Occator Crater is made of salt-rich material, which was likely once mixed in water.

Bright material is found on the rims of craters of the second category, streaking down toward the floors. It was already in the subsurface or had formed in a previous impact event.

In the third category, bright material can be found in the material ejected when craters were formed.

And the last category is owned by Ahuna Mons mountain, which is formed by the gradual accumulation of thick, slowly flowing icy materials, has prominent bright streaks on its flanks.

“We also see fractures on other solar system bodies, such as Jupiter’s icy moon Europa. The fractures on Europa are more widespread than the fractures we see at Occator. However, processes related to liquid reservoirs that might exist beneath Europa’s cracks today could be used as a comparison for what may have happened at Occator in the past.” ynnae Quick, a planetary geologist at the Smithsonian Institution in Washington, has been delving into this question.

More than 300 bright spots have been located on the surface of Ceres. Scientists with NASA’s Dawn mission say the bright material indicates the dwarf planet is an active, evolving world.

Although Cerealia Facula is the brightest area on all of Ceres, it would resemble dirty snow to the human eye.

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