학술논문

Initial Orbit Determination and Event Reconstruction From Estimation of Particle Trajectories About (101955) Bennu.
Document Type
Article
Source
Earth & Space Science. Sep2020, Vol. 7 Issue 9, p1-13. 13p.
Subject
*PARTICLE tracks (Nuclear physics)
*ORBIT determination
*ASTEROIDS
*SPACE trajectories
*NEAR-earth asteroids
Language
ISSN
2333-5084
Abstract
The OSIRIS‐REx mission has observed multiple instances of particles being ejected from the surface of near‐Earth asteroid (101955) Bennu. The ability to quickly identify the particle trajectories and origins is necessary following a particle ejection event. Using proven initial orbit determination techniques, we can rapidly estimate particle trajectories and ejection locations. We present current results pertaining to the identification of particle tracks, an evaluation of the estimated orbits and the excess velocity necessary to induce the particle ejection from the surface, and the uncertainty quantification of the ejection location. We estimate energies per particle ranging from 0.03 to 11.03 mJ for the largest analyzed events and velocities ranging from 5 to 90 cm/s, though we exclude the highest‐velocity particles in this technique. We estimate ejection times for eight events and constrain six of the analyzed ejection events to have occurred between about 16:30 and 19:00 local solar time, with the largest events occurring between 16:30 and 18:05. Key Points: We present orbit determination techniques used to reconstruct particle ejections from near‐Earth asteroid BennuWe estimate energies per particle ranging from 0.03 to 11.03 mJ and velocities ranging from 5 to 90 cm/s for the largest analyzed eventsWe find ejection times between about 16:30 and 19:00 local solar time for most events analyzed [ABSTRACT FROM AUTHOR]