Abstract: electrostatically-driven regolith motion has been a source of controversy in the planetary science community since the surveyor observations of lunar horizon glow. Recent advances in…

This is a grant awarded by the National Aeronautics and Space Administration (NASA) to the University of Maryland, College Park (UMD) to conduct research on electrostatic dust motion on the asteroid Bennu. The $322,000 grant is designed to compare computational predictions of dust grain movement to observations from the OSIRIS-REx mission's OCAMS instrument suite during the spacecraft's site selection and touch-and-go phases. The research aims to evaluate electrostatic dust motion as a formation mechanism for observed surface features on Bennu and assess the potential for dust lofting during the mission's touch-and-go sample collection. This work complements the OSIRIS-REx mission's primary focus on Bennu's dynamics, geology, and mineralogy. The grant does not utilize a set-aside designation. The University of Maryland is a state-controlled higher education institution that regularly receives federal contracts and grants for research, technology development, and other academic activities.

Abstract: electrostatically-driven regolith motion has been a source of controversy in the planetary science community since the surveyor observations of lunar horizon glow. Recent advances in regolith charging models have solved the long-standing question of how grains become sufficiently charged to overcome gravity and cohesion. A variety of circumstantial observational evidence indicates the electrostatically-driven regolith motion occurs on airless bodies. Furthermore, electrostatic dust motion is most likely to occur on asteroids (as compared to the other airless bodies), due to their weak gravity. However, to date, there have been no attempts to observe electrostatic dust motion at an asteroid. We propose to conduct the first comprehensive search for electrostatic dust motion at an asteroid, using existing plasma and dust dynamics models. We propose to enhance the science return of the osiris-REX mission by comparing observations of near-surface dust detected by the ocams instrument suite during site selection and touch-and-go phases of the mission to numerical predictions of electrostaticallydriven dust motion. The science objectives of the proposed investigation are to: 1. Compare computational predictions of location and grain characteristics of electrostatically levitating dust grains to ocams observations. 2. Evaluate electrostatic dust motion as a formation mechanism for observed dust-laden features on bennu. 3. Assess the feasibility of electrostatic dust lofting during the touch-and-go mission phase, and look for any signatures of electrostatic dust motion during this activity. Relevance: we propose to investigate the morphological effects of the interaction of the solar wind plasma with bennu's surface, thereby complementing osiris-REX's exisiting focus on the dynamics, geology and mineralogy of bennu. The proposed investigation is complimentary to the osiris-REX mission's current plans to detect dust plumes, observe surface features and probe regolith properties via sample collection. Additionally, the proposed investigation would take advantage of osiris-REX's capability to serve as the first investigation of electrostatic dust motion at an asteroid, thereby enhancing the science return of the mission by observing phenomena that may be active on other small airless bodies, including the moon and mars' moons.