About two years ago, NASA’s OSIRIS-REx spacecraft briefly made history by “marking” 101955 Bennu to collect samples of the weathering layer from the surface of the asteroid. While the mission won’t return to Earth until the end of next year, NASA shared new information about the celestial body. In an update released this week (via Mixable), the agency revealed that OSIRIS-REx will sink into Bennu if the spacecraft does not activate its thrusters immediately after contacting the asteroid’s surface.
“It turns out that the particles that make up the exterior of Bennu are so loosely wrapped and gently bonded to each other that if a person stepped on Bennu, they would feel little resistance, like stepping into a popular plastic ball pit kids zone,” NASA said.
This is not what scientists thought they would find on Bennu. Observing the asteroid from Earth, one would expect its surface to be covered in smooth, beach-like material. bennu’s response to the OSIRIS-REx touchdown also puzzled scientists. After a brief interaction with the asteroid, the spacecraft left a 26-foot (8-meter) wide crater in its wake. In laboratory tests, the pickup process “left almost no trace.
After analyzing the spacecraft’s data, they found that it encountered the same resistance that a person on Earth would feel when squeezing the plunger on a French coffee pot, said Ron Ballouz, a scientist on the OSIRIS-REx team. “When we launched the thrusters off the surface, we were still falling into the asteroid.”
According to NASA, its findings on Bennu could help scientists better interpret remote observations of other asteroids. In turn, it could help the agency design future asteroid missions. “I think we’re still in the early stages of understanding what these objects are because they behave in a very counterintuitive way,” said Patrick Michel, a member of the OSIRIS-REx team.