We deter
mine the three-di
mensional shape of near-Earth Asteroid (101955) Bennu based on radar i
mages and optical lightcurves. Bennu was observed both in 1999 at its discovery apparition, and in 2005 using the 12.6-c
m radar at the Arecibo Observatory and the 3.5-c
m radar at the Goldstone tracking station. Data obtained in both apparitions were used to construct a shape
model of this object. Observations were also obtained at
many other wavelengths to characterize this object, so
me of which were used to further constrain the shape
modeling. The lightcurve data, along with an initial deter
mination of the rotation period derived fro
m the
m, si
mplified and i
mproved the shape
modeling.
Below we briefly describe the observations and shape modeling process. We discuss the shape model and the implications for the possible formation and evolution of this object. We also describe the importance and limitations of the shape model in view of the fact that this object is the target of the OSIRIS-REx spacecraft mission.