This composite-color view from NASA's Dawn mission shows Cornelia Crater, streaked with dark materials, on the giant asteroid Vesta. (Photo : NASA/JPL-Caltech/UCLA/MPS/DLR/IDA )
Two to three billion years ago, a carbon-rich object crashed into the asteroid Vesta and formed dark blemishes on its surface, according to scientists working on NASA's Dawn mission.
Holger Sierks of the Max Planck Institute for Solar System Research notes, "The aim of our efforts was not only to reconstruct Vesta's history, but also to understand the conditions in the early solar system."
The study, published in the journal Icarus, crafts a road-map of how carbon may have initially made its way to earth. Using the Dawn orbiter, scientists found that the ancient harbinger of carbon created Vesta's Veneneia basin.
For the study, the team "created a map showing the distribution of dark material on Vesta using the framing camera data," according to Lucille Le Corre of the Max Planck Institute for Solar System Research.
Previously, researchers were unaware that the asteroid's dark marks were created by alien objects. Rather, the proto-planet's past volcanic activity was thought to have caused the dark spots on its surface.
"The evidence suggests that the dark material on Vesta is rich in carbonaceous material and was brought there by collisions with smaller asteroids," says study lead author Vishnu Reddy.
Dawn is now headed towards the planet Ceres, a two-and-a-half year journey.