A NASA spacecraft intentionally crashed into an asteroid in humanity’s first planetary defense test.
The impact occurred at 7:14 pm ET and was greeted with applause from the mission team in Laurel, Maryland. The DART mission, or Double Asteroid Redirection Test, launched 10 months ago.
While asteroid Dimorphos was not at risk of hitting Earth, this demonstration could determine how to deflect space rocks that could pose a threat to Earth in the future.
“We are embarking on a new era of humanity, an era where we potentially have the ability to protect ourselves from something like a dangerous asteroid impact,” said Lori Glaze, director of NASA’s Planetary Science Division. “What an amazing thing. We’ve never had that ability before.”
At the time of impact, Didymos and Dimorphos were relatively close to Earth, within 6.8 million miles (11 million km).
The spacecraft’s goal, aside from the impact, is to affect an asteroid’s motion in space, but it will take time for scientists to determine if the asteroid’s orbit changed.
Dimorphos is a small asteroid moon orbiting the near-Earth asteroid Didymos. The asteroid system poses no threat to Earth, NASA officials said, making it a perfect target for testing a kinetic impact, which may be necessary if an asteroid is on track to hit Earth.
The event was the first large-scale demonstration of deflection technology that can protect the planet.
“For the first time in history, we will appreciably change the orbit of a celestial body in the universe,” said Robert Braun, head of the Space Exploration Sector at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.
Near-Earth objects are asteroids and comets with orbits that put them within 48.3 million kilometers (30 million miles) of Earth. Detecting the threat of near-Earth objects that could cause serious damage is a primary focus of NASA and other space organizations around the world.
collision course
Astronomers discovered Didymos more than two decades ago. Means “twin” in Greek. Didymos is approximately 2,560 feet (780 meters) wide.
Dimorphos, meanwhile, is 525 feet (160 meters) in diameter, and its name means “two forms.”
Images taken by the spacecraft’s Didymos Asteroid and Reconnaissance Camera for Optical Navigation revealed the first look at Dimorphos. The spacecraft also used them to autonomously guide itself to a rendezvous with the small moon.
During the event, images were beamed back to Earth at a rate of one per second, providing a “pretty impressive” view of the moon, said Nancy Chabot, a planetary scientist and DART coordination lead at the Applied Physics Laboratory. .
The spacecraft was speeding up to about 13,421 miles per hour (21,600 kilometers per hour) when it collided with Dimorphos.
This collision was recorded by LICIACube, or Light Italian CubeSat for Imaging of Asteroids, a companion cube satellite provided by the Italian Space Agency.
The briefcase-sized CubeSat was deployed from the spacecraft and traveled behind it to record what’s happening.
Three minutes after impact, the CubeSat flew over Dimorphos to capture images and video. The images, although not immediately available, will be transmitted to Earth in the weeks after the collision.
