Asteroid Ryugu was somewhat of a mystery when astronomers first spotted it back in 1999. But we now know that the spinning-top-shaped body floating some 217 million miles from Earth is a loose assemblage of fragments from a collision between two asteroids held together by their aggregate gravity. Scientists estimate Ryugu formed between 10 million to 20 million years ago—practically yesterday in cosmic time, but how the asteroid came to be has remained largely unknown. Now, new research lays bare Ryugu’s recent violent past.
To uncover secrets about this rubble-pile asteroid, the Japan Aerospace Exploration Agency (JAXA) dispatched the fridge-sized spacecraft Hayabusa2 to Ryugu. For the study, published Monday in Nature Astronomy, scientists used