Reconstruction of Bennu Particle Events From Sparse Data

Area of Science:

• Planetary Science
• Asteroid Dynamics
• Space Mission Analysis

Background:

• The OSIRIS-REx mission observed particle ejection events from asteroid Bennu.
• Limited observational data (two images) often prevents traditional orbit determination for ejected particles.

Purpose of the Study:

• To develop and validate a novel technique for estimating particle states from limited observational data.
• To reconstruct and analyze particle ejection events from asteroid Bennu using this new method.

Main Methods:

• Assumed simultaneous ejection from a single point with constant velocity for particles in an event.
• Developed a novel orbit determination technique utilizing only two observations per particle.
• Applied the technique to OSIRIS-REx NavCam 1 imagery of Bennu particle ejection events.

Main Results:

• Successfully estimated particle ejection states, including velocities ranging from 7 cm/s to 3.3 m/s.
• Determined that over 80% of events originated from midlatitudes and occurred post-noon (12:44–18:52 local solar time).
• Validated the technique by comparing results with higher-fidelity solutions from events with sufficient observations.

Conclusions:

• The developed method effectively constrains properties of particle ejection events using limited data.
• This approach enhances the analysis of dynamic processes on near-Earth asteroids.
• The findings provide insights into Bennu's particle ejection mechanisms and origins.