A group of scientists working with Dawn, the first spacecraft to orbit the dwarf planet Ceres, think that they've finally figured out the cause of those bright spots in craters on the small world — and sorry folks, it's not aliens.

The new analysis produced from lab simulations and observations by Dawn, suggests that the brightest patch in at least one crater is actually produced by salts, according to a new study published in the journal Nature this week.

See also: NASA captures best photo yet of strange lights on dwarf planet Ceres

"Our data are consistent with the presence of hydrated magnesium sulfates in the brightest spot of the crater Occator," Martin Hoffmann and Andreas Nathues, two members of the research team that produced the study, told Mashable via email.

Researchers were surprised when Dawn began beaming back images of Ceres showing these bright, reflective spots in many of the craters on the small world's surface, and they immediately got to work trying to figure out what they were. NASA even polled the public, asking people to vote for their favorite explanation for the bright spots. (Salt has 11% of the vote, with ice at 28% and "other" at 39%.)

Hoffmann, Nathues and the rest of their team took to the lab to try to recreate the spectral signal seen by Dawn at Ceres, trying to figure out exactly what those bright spots are made of. They found a relatively close fit with these wet salts, and these findings match the researchers' overall understanding of Ceres — the largest object in the main belt of asteroids between Jupiter and Mars.

Scientists think that this finding lends more credence to the idea that Ceres is "differentiated" with an outer shell and inner core.

"The activity at Occator implies that even after millions of years after the actual impact, volatile material can still reach the surface. We hope that the higher resolution of the lowest, now upcoming orbit of the Dawn spacecraft will help us to see more details at the center of activity," Hoffmann and Nathues said.

So, that's it. It's wet salt?

But this mystery is still far from solved.

While the salt explanation does match what appears to be observed by Dawn, the data beamed back by the spacecraft isn't exactly the highest-resolution. The salt explanation is certainly plausible, but it's not definitive, planetary scientist Andy Rivkin told Mashable via email.

Like the scientists who conducted this study, Rivkin would also like to see more detailed images of the bright spots, plus more science collected by Dawn's Visual and Infrared Imaging Spectrometer instrument, designed to image Ceres in multiple wavelengths of light, to confirm (or disprove) the conclusions.

Overall, however, "wet salt" is a reasonable explanation for the bright spots at this point.

"The explanation for the bright spots as 'salts' is a perfectly reasonable one — they're highly reflective materials that don't have a lot of absorptions in the spectral region where FC [Dawn's Framing Camera instrument] is sensitive, so they match just fine," Rivkin said. "They're also associated with water, and water sublimation or evaporation, so that fits the overall story they're trying to piece together."

An outer solar system body?

Another study in Nature attempts to piece together the ancient history of the world.

Other data collected by Dawn appears to suggest that Ceres may have formed in the outer solar system and then migrated in to its current position, according to the study released this week.

"The data tell us that Ceres surface is composed by hydrated materials containing ammonia," study co-author Maria Cristina De Sanctis said told Mashable via email.

"Ammonia ice is difficult to have at the distance of Ceres because it sublimates at low temperature, lower than the present surface temperatures of Ceres," De Sanctis said. "Thus we think that ammonia was incorporated from material formed in the outer solar system where the temperatures are lower."

It's possible that Ceres either migrated into the inner solar system after forming in the outer planetary system, or "icy pebbles" of material from the outer solar system rained onto Ceres within a few million years after solid material started forming on the planet, De Sanctis said.

Those explanations, while they are perhaps plausible, are somewhat difficult to draw from this limited data, Rivkin said.

"I'm not yet fully convinced that ammoniated minerals are definitely there rather than some other choices like brucite," Rivkin said. "The fits do look very good, though. The De Sanctis paper claims that the presence of ammoniated material would require an outer solar system input. I'm also not convinced of that — there are amino acids in carbonaceous chondrites [a type of asteroid], for instance, and those are thought to be from the inner solar system."