Similarly, Japan's two Hayabusa missions hauled back to Earth specimens of the rubble piles, asteroid Itokawa (2010) and asteroid Ryugu (2020). You may like 'Planetary defense is knowing what's ...

New research found that the rubble-pile asteroid Itokawa is almost as old as the solar system itself and can survive collisions for 10 times longer than its conventional, single-body counterparts.

But Cantillo and colleagues said that rather than being an exposed intact core of an early planet, 16 Psyche could actually be more similar to a "rubble pile," like the asteroid Bennu.

Also, knowing if an asteroid is a single, big rock or a pile of rubble will have a major influence on how to nudge it off course, Scheeres said, should its orbit be aimed at Earth.