%0 Journal Article
%T Shape of (101955) Bennu indicative of a rubble pile with internal stiffness
%J -
%D 2019
%R https://doi.org/10.1038/s41561-019-0330-x
%X The shapes of asteroids reflect interplay between their interior properties and the processes responsible for their formation and evolution as they journey through the Solar System. Prior to the OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security¨CRegolith Explorer) mission, Earth-based radar imaging gave an overview of (101955) Bennu¡¯s shape. Here we construct a high-resolution shape model from OSIRIS-REx images. We find that Bennu¡¯s top-like shape, considerable macroporosity and prominent surface boulders suggest that it is a rubble pile. High-standing, north¨Csouth ridges that extend from pole to pole, many long grooves and surface mass wasting indicate some low levels of internal friction and/or cohesion. Our shape model indicates that, similar to other top-shaped asteroids, Bennu formed by reaccumulation and underwent past periods of fast spin, which led to its current shape. Today, Bennu might follow a different evolutionary pathway, with an interior stiffness that permits surface cracking and mass wasting
%U https://www.nature.com/articles/s41561-019-0330-x