Let it sink in! Asteroid Bennu’s surface found to be like a plastic ball pit
- The new observations contradict previously- drawn conclusions about the asteroid.
- Its surface is found to be like a pit of plastic balls.
- An actual sample of that surface will return to Earth in 2023.
Data gathered when NASA’s OSIRIS-REx spacecraft collected a sample from asteroid Bennu in October 2020 has revealed that the particles making up Bennu’s exterior are so loosely packed and lightly bound to each other that they resemble a pit of plastic balls that are popular play areas for kids, according to a statement by NASA published on July 7.
Void space on the surface
“If Bennu was completely packed, that would imply nearly solid rock, but we found a lot of void space in the surface,” said Kevin Walsh, a member of the OSIRIS-REx science team from Southwest Research Institute, which is based in San Antonio.
This new revelation was not at all what the scientists expected.
“Our expectations about the asteroid’s surface were completely wrong” said Dante Lauretta, principal investigator of OSIRIS-REx, based at University of Arizona, Tucson, and Walsh.
The researchers reached this conclusion after the OSIRIS-REx spacecraft picked up a sample and beamed close-up images of the asteroid’s surface to Earth. “What we saw was a huge wall of debris radiating out from the sample site,” Lauretta said. “We were like, ‘Holy cow!’”
Hints that the asteroid’s surface may not be what it seemed were given by the abundance of pebbles strewn about when the spacecraft landed although it just gently tapped the surface. It also left an unusually large crater that was 26 feet (8 meters) wide.
More images were required
“Every time we tested the sample pickup procedure in the lab, we barely made a divot,” Lauretta said. That’s when the researchers decided to send the spacecraft back to take more images “to see how big of a mess we made,” Lauretta said.
NASA’s spacecraft first arrived at Bennu in December of 2018 and discovered a surface littered with boulders instead of the smooth, sandy beach they had expected based on observations from Earth- and space-based telescopes. The ancient asteroid sits over 200 million miles (321 million kilometers) away from Earth.
NASA’s team is also waiting for more samples from the celestial object that will arrive in 2023. In the meantime, the team is using several techniques to identify and measure the samples remotely. What will be discovered when the samples finally touch Earth? Only time will tell.
The latest findings about Bennu’s surface were published on July 7 in a pair of papers in the journals Science and Science Advances.