A Japanese spacecraft bombed an asteroid and it barely flinched

By Leah Crane

In 2019, Japan’s Hayabusa 2 spacecraft bombed the asteroid Ryugu, using explosives to shoot it with a 2.5-kilogram lump of copper to create an artificial crater. Scientists expected this impact to shake the ground, but its actual effect was far milder.

Images from Hayabusa 2 have shown that the surface of Ryugu has fewer small craters than we would expect for an asteroid of its size, which probably indicates that dust is being moved …