Episodes of particle ejection from the surface of the active asteroid (101955) Bennu

  title={Episodes of particle ejection from the surface of the active asteroid (101955) Bennu},
  author={Dante S. Lauretta and Carl W. Hergenrother and Steven R. Chesley and Jason M. Leonard and John Y. Pelgrift and Coralie D. Adam and Manar M. Al Asad and Peter G. Antreasian and R.‐L. Ballouz and Kris J. Becker and Carina A. Bennett and Brent J. Bos and William F. Bottke and Maja Brozovi{\'c} and Humberto Campins and Harold C. Connolly and Michael G. Daly and Alex B. Davis and Julia de Le{\'o}n and Daniella N. DellaGiustina and C. Y. Drouet d’Aubigny and Jason P. Dworkin and Joshua P. Emery and Davide Farnocchia and Daniel P. Glavin and Dathon R. Golish and Christine M Hartzell and Robert A. Jacobson and Erica R. Jawin and Peter Jenniskens and John N. Kidd and E. J. Lessac-Chenen and J.‐Y. Li and Guy Libourel and Javier Licandro and Andrew J. Liounis and C. K. Maleszewski and C. Manzoni and B. H. May and Leilah McCarthy and Jay W. McMahon and Patrick Michel and Jamie L. Molaro and Michael C. Moreau and Derek S. Nelson and W. M. Owen and Bashar Rizk and H. L. Roper and Benjamin Rozitis and Eric M. Sahr and Daniel J. Scheeres and Jeffrey A. Seabrook and S. H. Selznick and Y. Takahashi and Florian Thuillet and Pasquale Tricarico and David Vokrouhlick{\'y} and Catherine W. V. Wolner},
Bennu ejects material from its surface Most asteroids appear inert, but remote observations show that a small number experience mass loss from their surfaces. Lauretta and Hergenrother et al. describe close-range observations of mass loss on the near-Earth asteroid Bennu (see the Perspective by Agarwal). Shortly after arriving at Bennu, navigation cameras on the OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security—Regolith Explorer) spacecraft detected objects 1… 
Introduction to the Special Issue: Exploration of the Activity of Asteroid (101955) Bennu
Of the potential mechanisms behind this activity that were investigated in focused studies, meteoroid impacts, thermal fracturing, and ricochet—but not water ice sublimation—were found to be consistent with observations, suggesting that many near‐Earth asteroids may exhibit activity that has gone unnoticed thus far.
Meteoroid Impacts as a Source of Bennu's Particle Ejection Events
It is found that 7,000‐J impacts on Bennu occur with a biweekly cadence near perihelion, with a preference to strike in the late afternoon (~6 pm local time), which matches observations.
Close-up view of an active asteroid
Centimeter-sized debris was found ejected from the surface of the likely ice-free asteroid 101955 Bennu in images taken by NASA's OSIRIS-REx spacecraft, showing that asteroids are far from being inert bodies.
Photometry of Particles Ejected From Active Asteroid (101955) Bennu
Near‐Earth asteroid (101955) Bennu is an active asteroid experiencing mass loss in the form of ejection events emitting up to hundreds of millimeter‐ to centimeter‐scale particles. The close
Dynamical Evolution of Simulated Particles Ejected From Asteroid Bennu
In early 2019, the OSIRIS‐REx spacecraft discovered small particles being ejected from the surface of the near‐Earth asteroid Bennu.sww Although they were seen to be ejected at slow speeds, on the
Reconstruction of Bennu Particle Events From Sparse Data
This newly developed technique offers the capacity to meaningfully constrain the properties of particle ejection events from limited data and comparison with higher‐fidelity orbit determination solutions for the events with sufficient observations demonstrates the validity of this approach.
Widespread carbon-bearing materials on near-Earth asteroid (101955) Bennu
The OSIRIS-REx results constrain Bennu's evolution and provide context for the sample collected in October 2020, as well as finding evidence for organic and carbonate materials that are widely distributed across the surface but are most concentrated on individual boulders.
Variations in color and reflectance on the surface of asteroid (101955) Bennu
Maps of color and albedo on asteroid Bennu indicate complex evolution of its surface due to space weathering, and constrain Bennu's evolution and provide context for the sample collected in October 2020.
Bright carbonate veins on asteroid (101955) Bennu: Implications for aqueous alteration history
Global spectral observations by the OSIRIS-REx spacecraft have shown that carbon-bearing materials, including organics and/or carbonates, are widespread on the surface of near-Earth asteroid (101955) Bennu.
Global Patterns of Recent Mass Movement on Asteroid (101955) Bennu
The exploration of near‐Earth asteroids has revealed dynamic surfaces characterized by mobile, unconsolidated material that responds to local geophysical gradients, resulting in distinct morphologies


The Unexpected Surface of Asteroid (101955) Bennu
Early OSIRIS-REx observations of Bennu are considered to understand how the asteroid’s properties compare to pre-encounter expectations and to assess the prospects for sample return.
Craters, boulders and regolith of (101955) Bennu indicative of an old and dynamic surface
Small, kilometre-sized near-Earth asteroids are expected to have young and frequently refreshed surfaces for two reasons: collisional disruptions are frequent in the main asteroid belt where they
The dynamic geophysical environment of (101955) Bennu based on OSIRIS-REx measurements
Combining the measured Bennu mass and shape obtained during the Preliminary Survey phase of the OSIRIS-REx mission, a notable transition is found in Bennu’s surface slopes within its rotational Roche lobe, defined as the region where material is energetically trapped to the surface.
Properties of rubble-pile asteroid (101955) Bennu from OSIRIS-REx imaging and thermal analysis
Establishing the abundance and physical properties of regolith and boulders on asteroids is crucial for understanding the formation and degradation mechanisms at work on their surfaces. Using images
Some asteroids eject dust, unexpectedly producing transient, comet-like comae and tails. First ascribed to the sublimation of near-surface water ice, mass-losing asteroids (also called “main-belt
The OSIRIS‐REx target asteroid (101955) Bennu: Constraints on its physical, geological, and dynamical nature from astronomical observations
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,
The operational environment and rotational acceleration of asteroid (101955) Bennu from OSIRIS-REx observations
The authors show the operational environment of asteroid Bennu, validate its photometric phase function and demonstrate the accelerating rotational rate due to YORP effect using the data acquired during the approach phase of OSIRIS-REx mission.
While having a comet-like appearance, P/2012 F5 (Gibbs) has an orbit native to the Main Asteroid Belt, and physically is a km-sized asteroid which recently (mid 2011) experienced an impulsive mass
Collisional balance of the meteoritic complex
Shape of (101955) Bennu indicative of a rubble pile with internal stiffness
The shape model indicates that near-Earth asteroid Bennu formed by reaccumulation and underwent past periods of fast spin, which led to its current shape, similar to other top-shaped asteroids.