Scientists Unravel Mystery of Bright Spots on Dwarf Planet Ceres

Spots were speculated to be everything from alien cities to geysers.

ByABC News
December 10, 2015, 11:19 AM

— -- Scientists have finally cracked the mystery of the unexplained lights on the dwarf planet Ceres that were speculated to be everything from alien cities to ice volcanoes.

After months of research gathered from the Dawn spacecraft, two new studies published in the journal "Nature" are shedding new light on what the 130 bright spots observed on Ceres could be and the surprising place where the dwarf planet may have formed.

In the first study, scientists determined those unusual areas of brightness are likely deposits of a salty substance comprised of magnesium sulfate, similar to epsom salt on Earth. The deposits were likely left when water-ice sublimated, scientists said. The impact from asteroids would have then unearthed the salty mixture, according to the study.

The second study reported the detection of ammonia-rich clays, suggesting Ceres may have not formed in the asteroid belt and instead may have been born in the outer solar system.

"The presence of ammonia-bearing species suggests that Ceres is composed of material accreted in an environment where ammonia and nitrogen were abundant," Maria Cristina De Sanctis, a scientist who has studied Ceres, said in a statement. "Consequently, we think that this material originated in the outer cold solar system,"

Nearly 600 miles in diameter, about 25 percent of Ceres' mass is believed to be ice. NASA's Dawn mission has been orbiting Ceres since March and will continue studying the dwarf planet through June 2016.

Just this week, the spacecraft reached an orbiting altitude of 240 miles from Ceres' surface. NASA said Dawn will then take observations from its new vantage point, capturing images at 120-feet per pixel.