Many of these are similar to those found on planets such as silicates and oxides. However, the interiors of some asteroids are chemically distinct from the planets and many minerals are found only in meteorites (fragments of asteroids that land on Earth). Carbonaceous asteroids, like Bennu, contain a wide range of organic molecules such as amino acids. These minerals and chemicals formed in the beginning of our solar system – either through condensation in the protoplanetary disk or during geologic processing in the asteroid interior.
The primary objective of OSIRIS-REx is to return pristine carbonaceous material from the early Solar System. This material will provide important clues to the origin of life on Earth and the likelihood that life may have originated elsewhere in our solar system. Our astronomical observations of Bennu suggest that there is abundant fine-grained (<1 cm) material on the surface available for sampling. Our sample collector design relies on loose gravel-like material for collection. Therefore, we expect to find loose, fine grain regolith on the surface of Bennu.