490 Veritas
At 115 and 125 km in diameter, Veritas and 92 Undina are the biggest of the 300-strong Veritas family of asteroids. David Nesvorný of the Southwest Research Institute in Boulder traced the orbits of these bodies back in time, and calculated that they formed in a collision of a body at least 150 km in diameter with a smaller asteroid some 8 million years ago. Veritas and Undina would have been the biggest pieces of that collision.