February 12, 2019 – Several times since NASA’s OSIRIS-REx spacecraft entered orbit around its target asteroid Bennu on December 31, 2018, the OSIRIS-REx team detected multiple, bright, point sources near Bennu in the optical navigation (OpNav) images obtained by the spacecraft’s NavCam 1 imager. The science team is currently investigating the exact cause of this phenomenon, but it’s probable that these images record a number of small particles near the asteroid.
The mission team’s initial analysis determined that the particles do not pose a significant risk to the spacecraft in its current orbit, which is between 1 and 1.3 miles (1.6 and 2.1 km) from Bennu. The team will continue to study the particles and their sources. After the initial detection, the team increased the cadence of OpNav observations to better study the environment around Bennu and monitor for additional occurrences.
OSIRIS-REx is scheduled to leave its current orbit on February 28, when it will begin the mission’s Sample Site Selection campaign. During this next mission phase, the OSIRIS-REx spacecraft will make a series of flybys of Bennu at a distance of around 2 miles (3 km) to start mapping the asteroid in detail.