@article{63ccbb6efc654243ad6af6a19f142dcd,
title = "Near-zero cohesion and loose packing of Bennu's near subsurface revealed by spacecraft contact",
abstract = "When the OSIRIS-REx spacecraft pressed its sample collection mechanism into the surface of Bennu, it provided a direct test of the poorly understood near-subsurface physical properties of rubble-pile asteroids, which consist of rock fragments at rest in microgravity. Here, we find that the forces measured by the spacecraft are best modeled as a granular bed with near-zero cohesion that is half as dense as the bulk asteroid. The low gravity of a small rubble-pile asteroid such as Bennu effectively weakens its near subsurface by not compressing the upper layers, thereby minimizing the influence of interparticle cohesion on surface geology. The underdensity and weak near subsurface should be global properties of Bennu and not localized to the contact point.",
author = "Walsh, {Kevin J.} and Ballouz, {Ronald Louis} and Jawin, {Erica R.} and Chrysa Avdellidou and Barnouin, {Olivier S.} and Bennett, {Carina A.} and Bierhaus, {Edward B.} and Bos, {Brent J.} and Saverio Cambioni and Connolly, {Harold C.} and Marco Delbo and DellaGiustina, {Daniella N.} and Joseph DeMartini and Emery, {Joshua P.} and Golish, {Dathon R.} and Haas, {Patrick C.} and Hergenrother, {Carl W.} and Huikang Ma and Patrick Michel and Nolan, {Michael C.} and Ryan Olds and Benjamin Rozitis and Richardson, {Derek C.} and Bashar Rizk and Ryan, {Andrew J.} and Paul S{\'a}nchez and Scheeres, {Daniel J.} and Schwartz, {Stephen R.} and Selznick, {Sanford H.} and Yun Zhang and Lauretta, {Dante S.}",
note = "Publisher Copyright: {\textcopyright} 2022 The Authors.",
year = "2022",
month = jul,
doi = "10.1126/sciadv.abm6229",
language = "English (US)",
volume = "8",
journal = "Science Advances",
issn = "2375-2548",
publisher = "American Association for the Advancement of Science",
number = "27",
}