Scientists confirmed Tuesday that NASA’s DART probe collided with the asteroid Demorphos, smashing it into the rock enough to change its course.
Demorphos is described as a small satellite, orbiting the larger asteroid Didymos, more than 11 million kilometers (6.8 million miles) from Earth. The satellite orbited its mother every 11 hours and 55 minutes until DART struck Demorphos on September 26. Its orbit is now shorter, lasting 11 hours and 23 minutes. The collision changed space travel forever.
The mission is the first test to demonstrate how machines manufactured on Earth might one day deflect a potentially dangerous asteroid, and the first time humans have succeeded in altering the orbit of a celestial body. Telescopes around the world tracking Demorphos’ orbit around Didymus have confirmed that its orbit has changed, NASA reports.
The Hubble Space Telescope captured debris tail from the collision of DART with Dimorphos… Image Credit: NASA/ESA/STScI
“We did the first ever planetary defense test,” NASA Administrator Bill Nelson said at a press conference Tuesday, catching the attention of millions of people around the world because DART felt like a movie plot, but that wasn’t Hollywood.
Space agencies and laboratories on Earth have been working on planetary defense strategies and technologies for decades prior to this mission. Several NEO monitoring programs have been launched to detect asteroids that might pose a threat to our fragile homeland and to calculate impact risks.
If these asteroids are discovered and accessed in time, the next deadly space rock scattering appears to be the best option to save our world from destruction.
Tracking potentially dangerous asteroids orbiting our galaxy is all well and good, but space agencies need to have the ability to shove Earth out of harm’s way once they identify a terrifying rock. DART shows that kinetic impactors can successfully deflect an asteroid and steer it away from the sky.
Below is a video of DART’s communication with Dimorphos, captured by NASA’s Asteroid Early Warning System (ATLAS).
Atlas monitoring of the collision of the spacecraft DART in Didimos! pic.twitter.com/26IKwB9VSo
Atlas Project (fallingstarIfA) September 27 2022
Scientists expected the DART collision to shorten Demorphos’ orbit by 10 minutes, but actually shortened it by 32 minutes. The results are within the probability predicted by the model, said Nancy Chabot, head of DART coordination at the Johns Hopkins Laboratory of Applied Physics. She added that the deflection effect was enhanced by Demorphos dropping rocks from their surface upon impact. The debris ejected from the asteroid soon formed a 10,000 km (6,210 mi) long tail (see above).
“This shows that the orbital period of Demorphos around Didymus changed by 4%, which is only a small change,” Chabot says. “But if you want to do that in the future, which might work, you would have to do it years ago so that this kind of asteroid deflection might be used in the future. Warning time is really important to do that, and as part of a much larger planetary defense strategy.”
The European Space Agency will launch another mission, HERA, to send a spacecraft and two cube satellites to study the effects of the DART collision in more detail in 2024.
“We all have a responsibility to protect our planet,” Nelson added. “At the end of the day, that’s the only thing we have, and this mission shows that NASA is preparing for what space throws at us.” ®
