Program: GN-2010B-C-6

We propose to make high-resolution observations of asteroids using AO, to measure size, shape, and pole position, and to search for satellites. We have demonstrated that AO imaging allows determination of the pole/dimensions in 1 or 2 nights, rather than the years of observations with lightcurve inversion techniques that only yield poles and axial ratios, not true dimensions. Using NGS AO, we will measure several large/intermediate asteroids. Accurately determining the volume from the often-irregular shape allows us to derive densities to greater precision in cases where the mass is known. We just derived a density for (21) Lutetia, prior to the Rosetta flyby. For the resolved-disk targets and for smaller asteroids, we will make satellite searches to expand our survey of the presence/characteristics of satellites in various populations, particularly NEOs (as we recently demonstrated by producing the first-ever optical image of an NEO binary ([Merline et al. 2008b, IAUC 8977]). Satellites allow an accurate mass to be determined, and also provide a real-life lab for testing collisional models. We will also target, as calibrators, objects of known size (Pluto and satellites of Saturn or Jupiter). We will also make deep/close searches for satellites with the NICI imager, particularly of Ceres, contributing to DAWN mission planning, as we have done for Rosetta.