CAPE CANAVERAL, Fla. (AP) — A spacecraft that slammed into a small, harmless asteroid millions of miles away has successfully shifted its orbit, NASA said Tuesday as it announced the results of its world rescue test.
The space agency attempted the test two weeks ago to see if, in the future, a killer rock could be pushed out of Earth’s way.
“This mission shows that NASA is trying to be ready for whatever the universe throws at us,” NASA Administrator Bill Nelson said during a briefing at the space agency’s headquarters in Washington.
The Dart spacecraft dug a crater in the asteroid Dimorphos on September 26, launching debris into space and creating a comet-like trail of dust and rubble spanning several thousand miles (kilometres). It took back-to-back nights of telescope observations from Chile and South Africa to determine how much the impact altered the asteroid’s 525ft (160m) path around its companion rock much bigger space.
Before impact, the moon took 11 hours and 55 minutes to orbit its parent asteroid. Scientists had planned to gain 10 minutes, but Nelson said the impact shortened the asteroid’s orbit by 32 minutes.
“Let’s all take a moment to soak this in…for the first time ever, humanity has changed the orbit” of a celestial body, noted Lori Glaze, director of planetary sciences at NASA.
Apollo astronaut Rusty Schweickart, co-founder of the nonprofit B612 Foundation, dedicated to protecting Earth from asteroid strikes, said he was “clearly thrilled, no doubt at this subject” by the results and the attention that the mission brought to the deflection of asteroids.
Team scientists said the amount of debris apparently played a role in the outcome. The impact may also have left Dimorphos reeling a bit, said NASA program scientist Tom Statler. It may affect the orbit, but it will never return to its original location, he noted.
The two bodies were originally already within a mile (1.2 kilometres) of each other. Now they are tens of yards (meters) closer.
Neither asteroid posed a threat to Earth – and still does as they continue their journey around the sun. That’s why scientists chose the pair for this all-important dress rehearsal.
Planetary defense experts would rather fend off a threatening asteroid or comet, given years or even decades, than blow it up and create multiple pieces that could rain down on Earth.
“We really need to have that warning time as well for a technique like this to be effective,” said mission leader Nancy Chabot of Johns Hopkins University’s Applied Physics Laboratory, who built the spacecraft and managed the $325 million mission.
“You have to know they’re coming,” Glaze added.
Launched last year, the vending machine-sized Dart – short for Double Asteroid Redirection Test – was destroyed when it slammed into the asteroid 7 million miles (11 million km) away at 14,000 mph (22,500 km/h).
“It’s a huge feat, not only for achieving the first step to possibly be able to protect us from future asteroid impacts”, but also for the amount of images and data collected internationally, Daniel Brown , an astronomer at Nottingham Trent University in England, said via email.
Brown also said it was “particularly exciting” that the tail of the debris could be seen by amateur skywatchers with medium-sized telescopes.
The team’s scientists warned that more work is needed not only to identify more of the countless space rocks, but also to determine their composition – some are solid, while others are piles of rubble. Reconnaissance missions might be needed, for example, before launching impactors to deflect orbits.
“We shouldn’t be too eager to say that a test on one asteroid tells us exactly how all other asteroids would behave in a similar situation,” Statler said.
Nevertheless, he and others are happy about this first effort.
“We’ve been imagining this for years and finally seeing it become real is really exciting,” he said.
The Associated Press Health and Science Department is supported by the Howard Hughes Medical Institute Department of Science Education. The AP is solely responsible for all content.
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