NASA’s OSIRIS REx spacecraft, which was launched almost two years ago, touched down on Bennu to take soil samples. Scientists believe that the probe was almost “swallowed by” an asteroid during this operation.
If the spacecraft had not started its engines right away after collecting rock and dust samples from Bennu’s surface, it would have fallen into Bennu. The particles on Bennu’s surface were so loosely packed that they are not connected. This meant that people would feel little resistance if they stepped on them. It was almost as if they were walking in a playground filled with plastic balls. We were still sinking into the planet by the time our engines started to leave the surface.
Scientists claim they were expecting something entirely different. Scientists believed the asteroid’s surface was denser than it actually is, and looked more like a heap of gravel. Instead, the surface was soft and fluid.
Scientists will be able to use the new data to understand these asteroids better. Particularly, if such an object falls to Earth it will behave differently than an ordinary metal or stone asteroid. This is especially important in Bennu’s case, as it is the most dangerous asteroid in our solar system. Its collision with Earth in 2182 is very likely at 0.04%. Bennu’s diameter is approximately 500m, meaning that its fall could have devastating consequences.