It was caused Causation by an approximately near-Earth asteroid with a speed of 19.16 ± 0.15 kilometres per second ( 60,000–69,000 km/h or 40,000–42,900 mph ) .

The earlier-predicted and well-publicized close approach Arriving of a larger asteroid on the same day , the roughly 367943 Duende , occurred Presence about 16 hours later ; the very different orbits of the two objects showed they were unrelated to each other .