https://techcrunch.com/2022/09/27/nasas-dart-anti-asteroid-satellite-successfully-smashes-into-space-rock/

NASA has completed a key step of its “Double Asteroid Redirection Test” (DART), smashing a satellite roughly the size of a vending machine into a small moon that’s about half-a-mile in diameter. The moon, Dimorphos, is orbiting an even larger asteroid, Didymos, and while neither is in any danger of colliding with Earth, they’re good test cases to see whether us puny humans smashing them with technology can cause them to change course.

DART is basically a demonstration of what would be a ‘Hail Mary’ pass in the case of any asteroid actually threatening Earth — namely, can we use a human-made spacecraft to redirect any planet-killers enough that they end up safely whizzing by our home planet instead of causing a repeat of the extinction even that wiped out the dinosaurs.