Dawn probe studies Ceres for a year: interesting discoveries and new puzzles

On March 6, 2015, the Dawn probe entered the orbit of Ceres, the largest body in the asteroid belt. Since then, the spacecraft has sent a ton of photographs and scientific data about Ceres. Dawn is a kind of “window in the asteroid belt” through which earth scientists look at objects distant from it.

Ceres does not skimp on surprises. So, it has long been known that there are bright spots on the surface of a planetoid. The probe photographed them in all details, and the situation became clear, scientists explained the nature of the spots. But now another interesting mystery has appeared - a five-kilometer mountain with bright slopes.


If you look at the photo for a long time, it seems that this is not a mountain, but a pit with steep slopes (photo: NASA).

It is called Ahuna Mons.. From a distance of 46,000 km, the mountain looked like a small bulge, and they did not pay much attention to it. But as Dawn approached the planetoid, it became clear that it was a pyramidal mountain with bright, smooth and steep slopes.


(photo: NASA)

The last photograph of Ahuna Mons was taken from a distance 120 times smaller than in February 2015. Scientists began to look for similar objects on the surface of Ceres, but it turned out that the mountain is the highest formation on the planetoid, there are no more similar objects in structure and size.

“No one expected to see a mountain on Ceres, especially one as big as Ahuna Mons. And we still do not have a satisfactory model for the formation of such a mountain, ”says Chris Russell, one of the leaders of the Dawn project.

As for the spots mentioned above, there were not two, but more than ten of them in the Occator crater. About 130 spots were counted on the entire planetoid, most of which are located near impact craters. After analyzing the brightness and structure of the spots, it was concluded that it was not ice and not salt, but something in between . More precisely, a certain type of aqueous magnesium sulfate is hexahydrite (Mg [SO4] 6H2O).


(photo: NASA)

There is also speculation that this substance is a phyllosilicate rich in ammonia. In this case, Ceres was formed outside the solar system, or within the system, but from material that arrived from outside the solar system.

What makes the slopes of the mountain, which was mentioned above, and whether this material is the same as the material of the stains, is still unclear. But Dawn continues to study Ceres, so soon this mystery should also be clarified. Scientists will present new pictures and more detailed data on March 22, during a press conference in Woodlands, Texas.