Ceres' Bright Mystery Spots Are (Probably) Salt

Earlier this year, NASA teased us with a mystery: very bright spots on the otherwise seemingly dim planet Ceres. Every month or so, NASA would publish a new image taken as its Dawn spacecraft grew closer. Soon, the mystery spot was clearly shown as two mystery spots, and not too long after that those two spots turned out to be many more smaller spots. All sorts of theories, official and unofficial, surfaced. Now NASA has an answer.

If you were hoping the answer would be something like "super secret alien air base," you're going to be disappointed, again. The answer is very likely one NASA has been saying all along: salt. Using the glut of data gathered by Dawn, NASA has found the bright spots are probably made of hydrated magnesium sulfates, which you may know as Epsom salt.

Researchers found there are 130 of these bright spots on Ceres, which itself is relatively small at only 590 miles across. It was noted that such bright spots were often found with impact craters; data from the spacecraft's framing camera helped nudge researchers away from the 'ice' speculation and more firmly toward 'salt.'

However, it is thought ice does play a role in the formation of these bright spots. Haze has previously been spotted, and researchers believe it indicates water vapor as well as dust and other particles. Both the ice and salt are likely exposed to the surface by impacts, hence their correlation with impact craters.

SOURCE: Space.com