In February of 2013, skywatchers around the world turned their attention toward asteroid 2012 DA14, a cosmic rock about 150 feet (50 meters) in diameter that was going to fly closer to Earth than the spacecraft that bring us satellite TV.
Little did they realize as they prepared for the once-in-several-decades event that another bit of celestial debris was hurtling toward Earth, with a more direct heading. On Feb. 15, 2013, the Chelyabinsk meteor, a roughly 62-foot (19 meter)-diameter asteroid exploded over the city of Chelyabinsk, Russia, as it entered Earth’s atmosphere at a shallow angle. The blast shattered windows and damaged buildings, and nearly two thousand people were hurt, though thankfully no one died.
“It turned out that two completely independent asteroids were coming by that day,” said Philip Lubin, UC Santa Barbara professor of physics, and one of the many scientists anticipating 2012 DA14’s near-Earth rendezvous. “One of them we knew was going to miss the Earth. The other one, we didn’t even know it was coming.”