A gargantuan space rock over 2.5 times the size of the Empire State Building is set to whiz past planet Earth on Jan. 18, 2022—not unlike the one that, some theorize, put an end to the dinosaurs some 65 million years ago. But fear not! Despite the object’s official NASA designation as “potentially hazardous,” the careening megaton asteroid poses little threat to us terrestrials. Asteroids are minor planets or astronomical objects, mostly irregularly shaped rocks, that orbit our Sun (or other celestial bodies) like unresolved planets, while lacking the characteristics of a comet with a tail. This particular approaching asteroid was cumbersomely dubbed “Asteroid (7484) 1994 PC1” after the date it was discovered—Aug. 9, 1994—by Robert McNaught at Australia’s Siding Spring Observatory. As for the object’s potentially apocalyptic size, Asteroid (7484) 1994 PC1 measures around 3,280 feet across (approx. 1 km), about the same size as a stadium or three times …