It began with dust. Before there were asteroids, or planets, or people – about 4.6 billion years ago – a cloud of dust and gas swirled in the cosmos. At the center, a star began to form. With heat and shock waves, clumps of this...

When Asteroid Bennu was discovered on Sept. 11, 1999 by the Lincoln Near-Earth Asteroid Research project (LINEAR), it was called 1999 RQ36 -- a provisional designation assigned by the Minor Planet Center. After follow-up observations...