On Monday, NASA’s DART spacecraft blasted into a faraway asteroid at incredible speeds in the world’s first test of a planetary defence system meant to avoid a deadly asteroid collision with Earth.
Humanity’s first effort to modify the path of an asteroid or any celestial body took place 10 months after DART was launched, in a NASA webcast from the mission operations centre outside Washington, D.C.
The DART camera captured photographs as the cube-shaped “impactor” spacecraft, no bigger than a vending machine with two rectangular solar arrays, raced into the asteroid Dimorphos, roughly the size of a football stadium, at 7:14 p.m. EDT (2314 GMT), some 6.8 million miles (11 million kilometres) from Earth.
The $330 million mission, which took seven years to develop, was designed to see if a spacecraft could change an asteroid’s trajectory via pure kinetic force, pushing it off course just enough to keep Earth safe.
The experiment’s success or failure will not be known until more ground-based telescope measurements of the asteroid are made next month. However, NASA officials praised the spacecraft’s incredible success, saying it served its objective.
“NASA works for the benefit of humanity, so for us, it’s the ultimate fulfilment of our mission to do something like this – a technology demonstration that, who knows, someday could save our home,” said NASA Deputy Administrator Pam Melroy, a retired astronaut.
DART, launched by a SpaceX rocket in November 2021, spent most of its journey under the control of NASA’s flight directors, with management turned over to an autonomous onboard navigation system in the closing hours.
The bullseye strike on Monday evening was tracked in near real-time from the mission operations centre at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.
Cheers erupted from the control room as DART’s onboard camera captured second-by-second pictures of the target asteroid, finally covering the TV screen of NASA’s live webcast moments before the signal was lost, signalling the spacecraft had collided with Dimorphos.
DART’s celestial target was an oblong asteroid “moonlet” roughly 560 feet (170 metres) in diameter that orbits Didymos, a parent asteroid five times bigger, as part of a binary pair called Didymos, the Greek word for twin.
Neither item poses a genuine threat to Earth, and NASA scientists stated that their DART test could not have accidentally created a new hazard.
The mission was a rare situation in which a NASA spacecraft had to crash to succeed. Instead, DART collided with Dimorphos at 15,000 miles per hour (24,000 kilometres per hour), producing the force that scientists think would be enough to push the asteroid’s orbit closer to the parent asteroid.
According to APL engineers, the spacecraft was blasted to shreds and left a minor impact crater on the asteroid’s boulder-strewn surface.
The DART team intends to abbreviate Dimorphos’ orbital route by 10 minutes. Still, it would consider a success of at least 73 seconds, demonstrating the exercise as a realistic approach to deflect an asteroid on a crash track with Earth – if one were ever discovered.
DART is the most recent of numerous NASA missions to examine and interact with asteroids, which are primordial rocky remains of the solar system’s formation around 4.5 billion years ago.
Last year, NASA dispatched a mission to the Trojan asteroid groups orbiting near Jupiter. In addition, the grab-and-go spacecraft OSIRIS-REx was on its way back to Earth with a sample collected from the asteroid Bennu in October 2020.