ALL asteroids of the inner main belt -even if they don't officially belong to a family- originate from the splintering of few large precursor planetesimals. Dermott et al.: https://t.co/3Xywd2l8BN pic.twitter.com/lp0z1xwWIt — Nature Astronomy (@NatureAstronomy) July 2, 2018

The study appeared today in the journal Nature Astronomy, and according to its lead author, University of Florida theoretical astronomer Stanley Dermott, the remaining 15 percent could end up being from the same handful of very old planets. The origin of the asteroid belt could tell us more about Earth, but more pressingly, those hunks of rock and mineral occasionally peel off and hurtle toward our own planet.

"These large bodies whiz by the Earth, so of course we're very concerned about how many of these there are and what types of material are in them," Dermott said in a press release. "If ever one of these comes towards the earth, and we want to deflect it, we need to know what its nature is."