The dwarf planet (the largest object in the main asteroid belt) resembles an ice moon in the outer solar system more than West, its asteroid neighbor.
Ceres and Vesta are the two largest bodies in the main asteroid belt. They may be contemporaries and neighbors, but this is where the similarities end. Ceres, as wide as Texas, is filled with frozen water and hydrated minerals, making it look more like the moon Jupiter or Saturn than its rocky and dry sister West.
Scientists can not yet understand why objects followed different paths of evolution. But they hope to get more information from NASA's Dawn spacecraft. He spent 14 months near Vesta before igniting the ion engine and settling in Ceres orbit in March 2015.
Research confirms the 30-year theory that Ceres was an ice-rich world.
“In its bark, we see about 10% (by weight) of water ice,” said Dawn's scientist Thomas Prittiman from the Institute of Planetology in Tucson, Arizona.
But the water in the bark is only the beginning of the story. Ceres abounds in minerals and clay, whose formation is possible only under liquid conditions. The estimated dwarf planet for 30% consists of water.
Vesta went the other way.
“So that it doesn’t happen there, but it has practically melted,” Prittimen said. After its radioactive elements decomposed (Vesta consists mainly of silicates), they cooled down and formed basalt crust, mantle and an iron-rich core.
“This should have happened close to the Sun, where volatile substances like water cannot be condensed because of the intense heat,” he added.
Maybe because of its remoteness from the Sun and the larger size, Ceres managed to save water, preparing the ground for chemical changes. Some models show that the separation of water and stone led to the formation of a frozen shell above the salty layer of liquid that remains today.
“Dawn is trying to return in time to the early stage of the Solar System,” Deputy Chief Researcher Carol Raymond from Pasadena Jet Propulsion Laboratory told reporters.
Interestingly, stone and water interact in such a way that the dwarf planet is chemically suitable for life.
Another group of scientists reported that Ceres was filled with large, dark craters (some with ice). Similar features are found at the poles of Mercury and of the Moon.
“Underground ice is omnipresent in Ceres. But he is a rare visitor on the surface, ”said astronomer Norbert Schorghofer from the University of Hawaii, Manoa.