Ground Truthing Bennu’s Shape Model
This graphic provides a preliminary demonstration of how closely the original radar-based shape model (Nolan et al., 2013) predicted Bennu’s actual shape, which is being slowly revealed during the OSIRIS-REx spacecraft’s approach to the asteroid.
The top row contains three images of Bennu obtained by the PolyCam camera on October 23, 2018, each taken about two hours apart. The images were taken from a distance of approximately 1,800 miles (3,000 km) from the asteroid and represent Bennu at 13 pixels in the camera’s field of view. The middle row shows renderings of Bennu as predicted by the published shape model, which was derived from ground-based radar observations from Arecibo Observatory and Goldstone tracking station and optical light curves. The shape model representations are rendered as if they were observed by the spacecraft at the same time and distance as the PolyCam images. The bottom row pixelates the shape model renderings to be similar to the observed PolyCam images to make comparison easier.
The images show overall agreement between the observations and the radar model predictions, including some of the large-scale features on the asteroid.
Date Taken: Oct. 23, 2018
Instrument Used: OCAMS (PolyCam)
Credit: NASA/Goddard/University of Arizona/Arecibo Observatory
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