First Spacecraft to Hit Asteroid in Attempt to Alter Its Trajectory

This illustration depicts NASA's DART probe, upper right, on course to impact the asteroid Dimorphos, left, which orbits Didymos. Steve Gribben/Johns Hopkins APL/NASA via AP

CAPE CANAVERAL, Fla.—In the first-of-its kind, save-the-world experiment, NASA is about to clobber a small, harmless asteroid millions of miles away.

A spacecraft named Dart will zero in on the asteroid Monday, intent on slamming it head-on at 14,000 mph (22,500 kph). The impact should be just enough to nudge the asteroid into a slightly tighter orbit around its companion space rock—demonstrating that if a killer asteroid ever heads our way, we’d stand a fighting chance of diverting it.