During the historic collection event, the sample head of the OSIRIS-REx spacecraft sank 1.6 feet (0.5 m) to the asteroid’s surface. Apparently, Bennu’s exterior is made up of loose particles that don’t bond with each other very securely, given what happens when the spacecraft collects samples. if the spacecraft He never fired his rocket again after rapidly collecting dust and rock, and may have sunk directly into the asteroid.
Bennu is an asteroid with an orbiting debris pile on top, made up of rocks bound together by gravity. It is about a third of a mile (500 m) wide.
Study co-author Kevin Walsh, member of the OSIRIS-REx science team at the Southwest Research Institute, said, “If Bennu was really full, it would be almost solid rock, but we found a lot of empty space on the surface. Boulder, Colorado, in its current state.
So what if the spacecraft’s thrusters don’t fire immediately?
“Osiris-Rex may have gone deep into the asteroid, which is exciting and scary at the same time,” said study co-author Patrick Mitchell, an OSIRIS-REx scientist and at the National Center for Scientific Research in Cité d’Or. ” research director. Azure Observatory in Nice, France.
Fortunately, the spacecraft and its valuable samples have returned to Earth. The Bennu model is set to arrive in September 2023.
Beno defies expectations
When the spacecraft reached Bennu in December 2018, the OSIRIS-REx team was surprised to find that the asteroid’s surface was covered with rock. Previous observations have taken them to sandy areas such as beaches.
Scientists see asteroid particles launched into space.
“Our predictions about the surface of the asteroid were completely wrong,” study author Dante Loretta, OSIRIS-REx principal investigator at the University of Arizona, Tucson, said in a statement.
The spacecraft took pictures of the location where it collected samples from Bennu, which further confused the team. Although Osiris Rex gently tapped the asteroid, it threw off a large amount of rock debris and left a 26-foot (8-meter) wide crater.
“What we saw was a giant wall of debris coming from the sampling site,” said Loretta, a professor of planetary science and cosmic chemistry at the University of Arizona’s Lunar and Planetary Laboratory. We are like, holy cow! “Whenever we test the sampling process in the lab, we can hardly differentiate.”
Before and after photos of the landing site show a big difference. The photo shows what appears to be a depression on the surface, at the base of which are several large rocks. The same sampling event causes this sunken landform. The asteroid’s dark surface also contains reflective dust near the collection point, which indicates where the rock was moved during the event. These changes are visible in the slider below.
By analyzing the spacecraft’s acceleration data, the team determined that it encountered a small amount of resistance, the same amount that might be felt when pushing a piston in a French coffee machine.
Understanding more about the formation of Bennu could help scientists study other asteroids, whether the target is planning missions such as OSIRIS-REx or protecting Earth from potential collisions with space rocks.
An asteroid like Bennu, which is barely capable of turning itself, could enter Earth’s atmosphere, posing another threat, even if it was not hit directly.
“We need to maintain physical contact with these things because that is the only way to determine their mechanical properties and response to external action,” Mitchell said. “Images are important, but they don’t tell us whether they are weak or strong.”
OSIRIS-REx – which stands for Origin, Spectral Interpretation, Resource Identification and Conservation – the Regolith Explorer – was NASA’s first mission to a near-Earth asteroid and, once there, traveled to a planet by spacecraft. Indicate the closest orbit to the object. , This time. Bennu is the smallest object ever orbited by a spacecraft.
The Bennu spacecraft memorial is the largest specimen collected by a NASA mission since the Apollo astronauts returned moon rocks.
Once Osiris Rex approaches Earth in 2023, it will detach the sampled capsule, shoot through Earth’s atmosphere and parachute into the Utah desert.
If OSIRIS-REx is still healthy after falling from the sample, it will launch a new campaign to study other asteroids.