• DOI:10.1111/maps.12353
• Corpus ID: 32777236

The OSIRIS‐REx target asteroid (101955) Bennu: Constraints on its physical, geological, and dynamical nature from astronomical observations

@article{Lauretta2015TheOT,
  title={The OSIRIS‐REx target asteroid (101955) Bennu: Constraints on its physical, geological, and dynamical nature from astronomical observations},
  author={Dante S. Lauretta and Arlin E. Bartels and Maria Antonietta Barucci and Edward B. Bierhaus and Richard P. Binzel and William F. Bottke and Humberto Campins and S R Chesley and Bunny C. Clark and Beth Ellen Clark and Edward A. Cloutis and Harold C. Connolly and Mary Katherine Crombie and Marco Delbo’ and Jason P. Dworkin and J. P. Emery and Daniel P. Glavin and Victoria E. Hamilton and Carl W. Hergenrother and Catherine L. Johnson and Lorenz Keller and P. Michel and M. C. Nolan and Scott A. Sandford and Daniel J. Scheeres and A. A. Simon and B. Sutter and David Vokrouhlick{\'y} and Kevin J. Walsh},
  journal={Meteoritics \& Planetary Science},
  year={2015},
  volume={50}
}

• D. Lauretta, A. Bartels, +26 authors K. Walsh
• Published 1 April 2015
• Physics, Geology
• Meteoritics & Planetary Science

We review the results of an extensive campaign to determine the physical, geological, and dynamical properties of asteroid (101955) Bennu. This investigation provides information on the orbit, shape, mass, rotation state, radar response, photometric, spectroscopic, thermal, regolith, and environmental properties of Bennu. We combine these data with cosmochemical and dynamical models to develop a hypothetical timeline for Bennu's formation and evolution. We infer that Bennu is an ancient object that has witnessed over 4.5 Gyr of solar system history. Its chemistry and mineralogy were established within the first 10 Myr of the solar system. It likely originated as a discrete asteroid in the inner Main Belt approximately 0.7–2 Gyr ago as a fragment from the catastrophic disruption of a large (approximately 100‐km), carbonaceous asteroid. It was delivered to near‐Earth space via a combination of Yarkovsky‐induced drift and interaction with giant‐planet resonances. During its journey, YORP processes and planetary close encounters modified Bennu's spin state, potentially reshaping and resurfacing the asteroid. We also review work on Bennu's future dynamical evolution and constrain its ultimate fate. It is one of the most Potentially Hazardous Asteroids with an approximately 1‐in‐2700 chance of impacting the Earth in the late 22nd century. It will most likely end its dynamical life by falling into the Sun. The highest probability for a planetary impact is with Venus, followed by the Earth. There is a chance that Bennu will be ejected from the inner solar system after a close encounter with Jupiter. OSIRIS‐REx will return samples from the surface of this intriguing asteroid in September 2023.