When a NASA robot scooped a cup of gravel from an asteroid 200 million miles away, scientists were stunned.
Bennu, an ancient space island the size of the Empire State Building, didn’t look or behave like they thought it would. Early temperature readings led them to believe it would be covered in tiny pebbles. Instead, closeup images showed boulders and a surface that acted like a plastic ball pit.
The OSIRIS-Rex mission team considered that the boulders could be full of holes, creating a very weak pile of rubble. Suddenly, understanding the space within the space rocks became an essential piece of the puzzle.