Getting To Know Asteroid Bennu

NASA’s first mission to return a sample from an ancient asteroid arrived at its target, the asteroid Bennu, on Dec. 3, 2018.
This mission, the Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer, or OSIRIS-REx, is a seven-year long voyage set to conclude upon the delivery to Earth of at least 2.1 ounces (60 grams) and possibly up to almost four and a half pounds (two kilograms) of sample.

It promises to be the largest amount of extraterrestrial material brought back from space since the Apollo era. The 20-year anniversary of the asteroid’s discovery was in September 2019 — and scientists have been collecting data ever since. Here’s what we already know (and some of what we hope to find out) about this pristine remnant from the early days of our solar system.

For example, the spacecraft’s navigation camera observed that Bennu was spewing out streams of particles a couple of times each week. Bennu apparently is not only a rare active asteroid (only a handful of them have been as of yet identified), but possibly with Ceres explored by NASA’s Dawn mission, among the first of its kind that humanity has observed from a spacecraft. This view of asteroid Bennu ejecting particles from its surface on January 19, 2019 was created by combining two images taken on board NASA’s OSIRIS-REx spacecraft. Other image processing techniques were also applied, such as cropping and adjusting the brightness and contrast of each image.

This view of asteroid Bennu ejecting particles from its surface on January 19, 2019 was created by combining two images taken on board NASA’s OSIRIS-REx spacecraft. Other image processing techniques were also applied, such as cropping and adjusting the brightness and contrast of each image.

Image credit: NASA/Goddard/University of Arizona larger image