In 1998, American actor Bruce Willis blew up an asteroid and himself to save Earth’s inhabitants from extinction. The asteroid in question, roughly the size of Texas, was fictional, but the film, Armageddon, encouraged the millions who watched it to consider the actual scenario of a strike by one of the many celestial bodies that brushes past us. The film was inspired by a convention of leading scientists a few years earlier. Ever since, decisions made at that convention have guided international efforts to take action when a rogue asteroid has Earth in its sights.
It’s tempting to think there’s little in Earth’s path as it hurtles through space, but in reality, it must dodge innumerable obstacles. Space is not a wilderness; it bristles with all manner of activity. Much of it stays far away, but some travel to our neck of the woods. Some we can see coming, others we can’t. These visitors have a name – near-Earth objects or NEOs – and not all are benign.
