In its first-ever planetary defence test, a NASA spacecraft successfully slammed into an asteroid, a demonstration technique for protecting our planet from an Earth-bound asteroid or comet.
The DART mission, or the Double Asteroid Redirection Test, impacted the asteroid Dimorphous on Monday, 10 months after flying in space.
Asteroid moonlet Dimorphos is a small body just 160 meters in diameter. It orbits a larger 780-meter asteroid called Didymos.
While the asteroid Dimorphos or Didymos were not at risk of colliding with Earth, NASA's demonstration highlights our capability to protect Earth from something like a dangerous hazardous asteroid impact.
"As NASA studies the cosmos and our home planet, we’re also working to protect that home, and this international collaboration turned science fiction into science fact, demonstrating one way to protect Earth," NASA Administrator Bill Nelson was quoted in the agency's official press release.
DART's one-way trip confirmed NASA can successfully navigate a spacecraft to intentionally collide with an asteroid to deflect it, a technique known as kinetic impact, the release added.
Don't want to miss a thing? Watch the final moments from the #DARTMission on its collision course with asteroid Dimporphos. pic.twitter.com/2qbVMnqQrD
— NASA (@NASA) September 26, 2022
The investigation team will now observe Dimorphos using ground-based telescopes to confirm that the DART hit has changed its orbit. The primary purpose of the full-scale test is to measure how much the asteroid was deflected, and researchers expect the impact may have shortened Dimorphos’ orbit by about one per cent or roughly 10 minutes.
Through the mission, NASA has made a reality of what has before only been attempted in science fiction in movies like 'Armageddon' and 'Don't Look Up.'
"For the first time ever, we will measurably change the orbit of a celestial body in the universe," CNN quoted Robert Braun, head of the Johns Hopkins University Applied Physics Laboratory’s Space Exploration Sector in Laurel, Maryland.
An array of telescopes were watching the event both on Earth and in space, including the recently operational James Webb. The mission had piqued the interest of global astronomy, with more than three dozen ground telescopes participating, including optical, radio and radar. "There's a lot of them, and it's incredibly exciting to have lost count," DART mission planetary astronomer Christina Thomas told AFP.
The European Space Agency’s era mission will arrive to study Dimorphos in four years. The probe will measure the physical properties of the moon and look at its orbit and the DART impact.
The momentum DART imparted on Dimorphos will depend on whether the asteroid is solid rock, or more like a "rubbish pile" of boulders bound by mutual gravity. But, that property is not yet known. Even if NASA had missed this time, it would have another shot in two years as the DART mission had enough fuel for another pass.
