Strange dark material on protoplanet Vesta likely carbon from asteroid impact
A new study related to NASA's Dawn mission found an answer on the whereabouts of dark spots on the giant asteroid Vesta. A carbon-rich asteroid possibly crashed into Vesta two to three billion years ago and formed dark blemishes on its surface.
For the study, the team "created a map showing the distribution of dark material on Vesta using the framing camera data," of the Dawn orbiter, according to Lucille Le Corre of the Max Planck Institute for Solar System Research in Lindau, Germany.
Vesta, which is also known as a proto-planet whose development was interrupted by Jupiter in its early stage, is the second-most-massive asteroid after the dwarf planet Ceres, is 523 kilometers wide, and could comprises as much as 9 percent of the mass of the whole asteroid belt betwen Mars and Jupiter. Like other protoplanets, Vesta was completely melted approximately 4.5 billion years ago, but then volcanic activity on Vesta is believed to have died down rather quickly within a few million years. It is therefore like a frozen time capsule from the early solar system, providing astronomers a way to analyze the processes that happened in the early formation period of our solar system.
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 data from the Dawn orbiter, scientists found that a massive, 40 to 60 km large asteroid which blasted the huge Veneneia basin into Vesta's surface, also carried the coal-black carbon with it.
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.
The dark patches are mostly spread around the edges of the two enormous impact basins in the southern hemisphere of Vesta, named Veneneia and Rheasilvia.
The Dawn spacecraft, after leaving Vesta's orbit in September 2012, is currently on its way towards Ceres, a two-and-a-half year journey.
The Dawn mission to Vesta and Ceres is managed by NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, for NASA's Science Mission Directorate, Washington. The University of California, Los Angeles, is responsible for overall Dawn mission science. The Dawn framing cameras were developed and built under the leadership of the Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany, with significant contributions by DLR German Aerospace Center, Institute of Planetary Research, Berlin, and in coordination with the Institute of Computer and Communication Network Engineering, Braunschweig.