Not long ago, NASA had its spacecraft called OSIRIS-REx make one final flyby of asteroid Bennu before departing for the long trip back to Earth. One reason for the flyby was so that the spacecraft can capture an image showing the aftermath of its encounter with the asteroid. On that final flyby, OSIRIS-REx flew within 2.3 miles of the asteroid, which is the closest it has been to Bennu since the sample collection event last October.
During the sample collection event, the spacecraft sampling head was jammed 1.6-feet into the asteroid’s surface, and a pressurized charge of nitrogen gas was fired. That caused the churning of surface material and drove some of the material into the spacecraft sample collection chamber. When OSIRIS-REx backed away from the asteroid’s surface, its thrusters also propelled rocks and dust away from the surface of the asteroid.
The image shared above shows the area where the spacecraft collected samples after the collection event. At the sample collection point, there is a depression with several large boulders seen near the bottom of the image. NASA says it appears that those boulders were exposed by the sampling event. NASA also points out an increase in the amount of highly reflective material near the touch-and-go point against the surface’s dark background.
Lots of rocks are also moved around on the surface of Bennu. Scientists estimate that one boulder in the image, which measures about four feet and is thought to weigh somewhere around a ton, was tossed about 40 feet from the landing site. Capturing the final flyby image required lots of planning because they had to be taken from very near the same position and the same time of day to be comparable.
OSIRIS-REx will remain near the asteroid until May 10. After that, the mission will begin its 24-month return trip to Earth. The spacecraft will approach the Earth and jettison its Sample Return Capsule which will enter the Earth’s atmosphere and land using parachutes at the Utah Test and Training Range on September 24, 2023.