Astronomers think they’ve found evidence that an asteroid broke up about 8.2 million years ago, scattering dust around the Solar System. The discovery was made by US and Czech Republic researchers who found a layer of helium 3 in oceanic sediment – this isotope is normally quite rare. This evidence matches computer simulations on a group of asteroid fragments in the asteroid belt that were once part of a larger object called Veritas. It was likely the biggest asteroid break up or collision in the last 100 million years.