The results are in from NASA’s Double Asteroid Redirection Test, or DART, which attempted to deflect an asteroid: NASA has forever reshaped the Didymos-Dimorphos system. The successful test points to a possible planetary defense strategy for protecting Earth against hazardous near-Earth...

NASA’s DART spacecraft is on track to hit a non-threatening asteroid today at 7:14 p.m. ET, in what is an important demonstration of a planetary defense strategy. But space is hard, and DART, traveling at 15,000 miles per hour, could whiz past the 520-foot-wide object. Here’s what would happen...

Later today, NASA’s DART spacecraft will attempt to smash into a non-threatening asteroid. It’s one of the most important things we’ve done in space—if not the most important thing—as this experiment to deflect a non-threatening asteroid could eventually result in a robust and effective...