The material in the asteroid belt presents us with a snapshot of the earliest epoch of the solar system's formation. Telescope observations have revolutionized what we know about the largest asteroids: they are more than simple space rocks: they are evolved, dynamic bodies with important information about solar system origins. The largest asteroids 1 Ceres, 2 Pallas and 4 Vesta grew massive enough to undergo varying degrees of compositional differentiation. Ceres and Vesta will be visited by the Dawn spacecraft, but there are currently no plans for a mission to Pallas. Thus, the Hubble Space Telescope provides the best available opportunity to study Pallas. Pallas is a B-type asteroid with inclination of 31o and estimated triaxial shape of 570x525x482 km. There is spectral evidence that Pallas, like Ceres, has been substantially altered by water. Pallas, at 2.77 AU, shares a similar environment as Ceres, but is similar in size and mass to Vesta. Thus, Pallas may provide information about how size and location affect a forming planetessimal's composition and thermal history. Planned September 3 observations of Pallas with Hubble's WFPC2 in five filters from 336-814 nm are discussed. These occur during Pallas’ opposition and include a satellite search.
AAS/Division for Planetary Sciences Meeting Abstracts #39
- Pub Date:
- October 2007