The mysterious bright spots on Ceres (the largest object in the asteroid belt between Mars and Jupiter) speculated to be, among many other things, alien outposts, are no alien related artifacts after all.
Early this year, NASA’s Dawn spacecraft sent home an image that showed two very bright spots inside a large crater on Ceres. That caused quite the stir. Ceres has more than 130 bright spots, usually at the site of impact craters.
Alien outpost aside, scientists speculated the spots were ice or salt, although some also theorized geysers or volcanoes.
Now, however, scientists say that Ceres’s bright spots are not alien cities. In a new study in the journal Nature, lead study author Andreas Nathues at the Max Planck Institute for Solar System Research in Germany writes that the bright material looks to be a kind of hydrated magnesium sulfate called hexahydrite (Epsom salt is a familiar magnesium sulfate to us Earthlings).
The brightest spot is seen in the Occator Crater, a large area that’s featured in a new video released by NASA, showing Ceres’ rotation. The video uses “false color” to emphasize differences in the composition of Ceres’ surface, as seen from an orbit altitude of about 2,700 miles.
A second study, also in Nature, finds ammonia-rich clays on the planet. This could mean Ceres was formed where Ammonia and Nitrogen were abundant, possibly the cold outer solar system. Ceres could have drifted in to its current position from its original location. It could have also formed in its current location with materials that drifted from the outer solar system.
Dawn still has lot left to do with Ceres. The spacecraft is currently preparing for its closest mapping orbit where it will image the surface of the dwarf planet from a distance of just 240 miles.