The spacecraft, NASA's Double Asteroid Rendezvous Test (DART) probe, slammed into a small asteroid 7 million miles (11 million kilometers) from Earth tonight (Sept. 26) in what the U.S. space agency has billed as the world's first planetary defense test. The goal: to change the orbit of the space rock — called Dimorphos — around its larger asteroid parent Didymos enough to prove humanity could deflect a dangerous asteroid if one was headed for Earth.

"As far as we can tell, our first planetary defense test was a success," said Elena Adams, DART's mission systems engineer here at the Johns Hopkins University Applied Physics Laboratory (JHUAPL), after the successful crash. "I think Earthlings should sleep better. Definitely, I will."

That's something the dinosaurs couldn't do 65 million years ago, when the massive Chicxulub asteroid slammed into the Yucatan Peninsula and led to their extinction.

"The dinosaurs didn't have a space program to help them, but we do," Katherine Calvin, NASA's chief scientist and senior climate advisor, said before the crash. "So DART represents important progress in understanding potential hazards in the future and how to protect our planet from potential impacts."

The golf cart-sized DART spacecraft slammed into Dimorphos at 7:14 p.m. EDT (2314 GMT) while flying at a whopping 14,000 mph (22,500 kph). The spacecraft wasn't large as probes go, but NASA hoped that its 1,320 pounds (600 kilograms) would be enough to move the 534-foot-wide (163 meters) Dimorphos a bit faster in its orbit around its parent. 

"The spacecraft is very small," said planetary scientist Nancy Chabot, DART coordination lead at JHUAPL, which oversees the mission for NASA, before the impact. "Sometimes, we describe it as running a golf cart into the Great Pyramid."