Data collected with the Dawn spacecraft probe suggest that the giant asteroid and proto-planet Vesta hosts carbon and hydrated minerals on its surface, but no iron.
UCLA astronomer Christopher Russell states, "Ever since Dawn arrived at Vesta and we saw the bright and dark streaks across the surface, we have wondered how the zebra got her stripes."
He adds, "Now we know that the bright streaks and spots are due to pure early Vestan material, and the dark patches are deposits on the surface most probably due to collisions with material from the dark outer reaches of the asteroid belt."
The LA Times reports that "the asteroid's brightness range is, in fact, the greatest observed in the solar system," and that its black streaks were deposited by smaller asteroids and solar winds.
The publication notes that most other airless bodies have become gray due to a coating of iron-rich dust particles.
Russell, who is also the principal investigator for the Dawn mission asserts that "Vesta has been recording the history of the solar system from the beginning-more than 4.5 billion years ago. We're going further back than ever before on the surface of a body."
Study co-author Tom McCord explains the find's implications: "It forces one to [suppose] most objects are contaminated this way, and this is the way the Earth got its water and organic material. It not only has implications for the surface of Vesta, but for other airless inter-solar system objects."
The study was originally published in the scientific journal Nature.