NASA has pulled off a world's first by successfully colliding a man-made spacecraft into a distant asteroid with the goal of altering its orbit.

NASA's Double Asteroid Redirection Test (DART) recently struck the binary asteroid system Didymos-Dimorphos, located approximately seven million miles from Earth. The DART spacecraft impacted the smaller of the two asteroids, Dimorphos, which orbits its larger companion asteroid, Didymos. NASA's goal was to prove that a spacecraft approximately the size of a vending machine, when traveling at extremely high speeds, is capable of changing the orbit of an asteroid - the world's first planetary defense demonstration.
Astronomers on Earth gazed up at the asteroid system on the day of the impact, looking for any changes in the asteroid. Italian astronomer Gianluca Masi live-streamed his observations via the Virtual Telescope project, which showcased Dimorphos gaining in brightness following the impact of the DART spacecraft. The above GIF showcases the increasing brightness, which, according to Masi, completely exceeded his expectations for the event.
The observations were conducted through a 12-inch telescope located at South Africa's Klein Karoo Observatory, and during the collision, Masi was joined by fellow astronomer Berto Monard, who explained that shortly after impact, the astronomers saw a large dust plume emerge around the asteroid. This dust plume expanded into a cloud that sent back light from the Sun, increasing the brightness of the asteroid. Monard also said that during the event, the shape of the asteroid changed, with some dust particles moving away, creating a halo shape similar to that of a comet.
"Soon after the impact, an amount of dust was released like a plume and now this cloud of dust is expanding, sending back light from the sun. This is much more than what I could expect. Even the shape is a bit different. It's like a comet. There are particles that are moving away from the asteroid and that's why you have a bigger halo of light," Monard explained.
Currently, there are countless telescopes aimed at the binary asteroid system as researchers attempt to learn more about the human-made impact on Dimorphos and if the small high-speed DART spacecraft was able to achieve its initial mission of reducing the moonlet's orbit around its larger, 2,560-foot-wide companion Didymos, by 1% or approximately 10 minutes. NASA will consider the mission a success if it changes Dimorphos' orbit by no less than 73 seconds or about 1 minute 20 seconds.
If proven to be an effective technique for asteroid orbit altering, NASA will have unlocked a new weapon humans can use to guard the planet from dangerous space rocks.