NASA’s DART spacecraft has successfully slammed into the asteroid Dimorphos, with enough impact to alter the rock’s orbit, scientists confirmed Tuesday.
Described as a small moon, Dimorphos orbits the larger asteroid Didymos more than 11 million kilometers (6.8 million miles) from Earth. Before DART met Dimorphos on September 26, the small moon orbited its parent star once every 11 hours and 55 minutes. Now its orbit is shorter, lasting 11 hours and 23 minutes; The collision permanently changed his journey through space.
The mission was a unique test that demonstrated how Earth-based machines could be used to one day deflect potentially dangerous asteroids, and marks the first time mankind has successfully altered the orbit of an astronomical object. Telescopes around the world tracking Dimorphos’ orbit around Didymos confirmed that its trajectory had changed, NASA reported.
A Hubble Space Telescope snapshot capturing the debris tail from DART’s collision with Dimorphos…Image credit: NASA/ESA/STScI
“We conducted humanity’s first planetary defense test,” NASA Administrator Bill Nelson said at a briefing Tuesday. “And we showed the world that NASA means business as a defender of this planet. We caught the attention of millions of people around the world in this test, and that’s because DART felt like a movie plot. But that wasn’t Hollywood.”
Space agencies and laboratories around the world worked on planetary defense strategies and technologies for decades prior to this mission. Several low-Earth object surveillance programs have been launched to detect asteroids potentially dangerous to our fragile homeworld and calculate the risk of a crash.
Rerouting incoming killer space rocks seems like the best option to save our world from destruction, assuming those asteroids are spotted and can be reached in time.
Tracking potentially dangerous asteroids whizzing through our galactic neighborhood is all well and good, although once a terror rock has been identified, space agencies must have the skills to get Earth out of the way. DART proves that kinetic impactors can successfully deflect asteroids and push them in a direction away from our sky.
Below is video of DART Prang with Dimorphos captured by NASA’s ATLAS asteroid early warning system:
ATLAS observations of DART spacecraft impact at Didymos! pic.twitter.com/26IKwB9VSo
— ATLAS project (@fallingstarIfA) September 27, 2022
Scientists hoped the DART collision would shorten Dimorphos’ orbit by 10 minutes, but it actually shortened it by 32 minutes. Nancy Chabot, the DART coordinator at the Johns Hopkins Applied Physics Laboratory, said this result is within the range of possibilities predicted by models. She added that the deflection effect was enhanced by Dimorphos throwing rocky material off its surface on impact. Debris ejected from the asteroid soon formed a 10,000-kilometer tail (see above).
“This is a four percent change in the orbital period of Dimorphos around Didymos, and it only gave it a small nudge,” Chabot said. “But if you want to do this in the future, it could potentially work, but you want to do it years in advance. The warning time is really critical here so that this type of asteroid deflection can potentially be used in the future and as part of a much larger planetary defense strategy.”
The European Space Agency will launch Hera, a separate mission that will send a spacecraft and two CubeSats to study more closely the aftermath of DART’s 2024 collision.
“We all have a responsibility to protect our own planet,” added Nelson. “After all, it’s the only one we have. And this mission shows that NASA is trying to be prepared for whatever the universe throws at us.” ®
https://www.theregister.com/2022/10/12/dart_spacecraft_asteroid_deflection/ NASA confirms DART probe crash changed asteroid’s orbit • The Register