The space rock-smashing mission was a success, the agency said.

The DART spacecraft hit an asteroid called Dimorphos on September 26, pushing it closer to Didymos, its parent asteroid.

Infographic showing the effect of DART spacecraft impact on the orbit of asteroid Dimorphos
DART was designed to push Dimorphos into a new orbit, closer to Didymos.
NASA/Johns Hopkins APL

It was a practice run to get ready for the real thing. No such space rock is currently on a collision course with Earth, according to NASA. Experts say it is only a matter of time.

Bill Nelson, NASA's administrator, said in a briefing on Tuesday that NASA is serious about defending this planet. This is a turning point for planetary defense and all of humankind.

sequence of images showing asteroid from a distance then close up then video cutting out
Screenshots of the footage from DART's camera as the spacecraft approached, then smashed into the rock, on September 26, 2022.

Nelson said it would have been a huge success to shorten Didymos's flight time. It took 73 seconds for DART to be successful.

Astronomers with Earth-based telescopes found that Dimorphos are now circling Didymos 32 minutes faster than before.

LICIACube image showing the aftermath of the DART impact.
LICIACube image showing the aftermath of the DART impact.

It took 11 hours for Dimorphos to circle Didymos. It only took 11 hours and 23 minutes with the help of DART.

The director of NASA's Planetary Science Division said that for the first time in history, humanity has changed the path of a planet.

illustration shows spacecraft with two long solar panel wings and blue engine fire approaching an asteroid
Illustration of DART approaching Dimorphos.
NASA/Johns Hopkins APL

The force of the golf cart-sized probe smashing into it gave part of Dimorphos's movement. Some of the movement was caused by recoil from the debris that flew off the asteroid.

A jet of air streaming from a balloon pushed Dimorphos away from the crash site and towards Didymos.

Astronomers are still observing the asteroid system, collecting and analyzing more data, to understand how much the ejection affected the change in the asteroid's trajectory.