Home » News & Blogs » OSIRIS-REx: Tracking Bennu’s Unusual Activity
Bookmark and Share
Centauri Dreams

OSIRIS-REx: Tracking Bennu’s Unusual Activity

10 Sep 2020, 13:06 UTC
OSIRIS-REx: Tracking Bennu’s Unusual Activity
(200 words excerpt, click title or image to see full post)

OSIRIS-REx, the little spacecraft with the big acronym (standing for Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer) has been on station for a year and a half at asteroid Bennu, monitoring the unexpected activity that distinguishes the object. Particle ejection from the surface is the subject of a revised special issue of the Journal of Geophysical Research: Planets collecting 10 papers on the matter.
Specifically, the spacecraft has found that particles of rock mostly of pebble-size are being ejected repeatedly — one or two per day — from the asteroid’s surface, some of them escaping into space, some moving into a temporary orbit, with the rest falling back onto the surface. Just days after entering orbit on December 31 of 2018, OSIRIS-REx began to spot the activity, which the introduction to the special issue refers to as “ongoing mass shedding” involving millimeter- to centimeter-scale particles. What we have on our hands here is an asteroid that is active.
Dante Lauretta (University of Arizona) is OSIRIS-REx principal investigator:
“We thought that Bennu’s boulder-covered surface was the wild card discovery at the asteroid, but these particle events definitely surprised us. We’ve spent the last year investigating Bennu’s active surface, and ...

Latest Vodcast

Latest Podcast

Advertise PTTU

NASA Picture of the Day

Astronomy Picture of the Day

astronomy_pod