NASA’s asteroid-deflecting spacecraft crashes into its target


A NASA spacecraft slammed into an asteroid at lightning speed on Monday in an unprecedented dress rehearsal for the day a killer rock threatens Earth.

The galactic snap happened on a harmless asteroid 7 million miles (9.6 million km) away, with the spacecraft named Dart plowing through space rock at 14,000 mph (22,500 km/h). Scientists expected the impact to carve out a crater, send streams of rock and soil into space and, most importantly, change the asteroid’s orbit.

« We have an impact! » announced Elena Adams of Mission Control, jumping up and down and throwing her arms skyward.

Telescopes around the world and in space aimed at the same point in the sky to capture the spectacle. Although the impact was immediately obvious – Dart’s radio signal abruptly ceased – it will take days, if not weeks, to determine just how much the asteroid’s trajectory has been altered.

« Now is where the science begins, » said Lori Glaze, director of NASA’s planetary science division. « Now we’re going to see for real how effective we were. »

The $325 million mission was the first attempt to shift the position of an asteroid or any other natural object in space.

« What an amazing thing. We’ve never had this ability before, » Glaze noted.

Earlier today, NASA Administrator Bill Nelson reminded people via Twitter that « no, this is not a movie plot. » He added in a pre-recorded video: « We’ve all seen it in movies like ‘Armageddon’, but the real stakes are high. »

Monday’s target: a 525-foot (160-meter) asteroid named Dimorphos. It’s actually a moon of Didymos, a twin in Greek, a fast-rotating asteroid five times its size that threw off the material that formed the junior partner.

The pair have orbited the sun for eons without threatening Earth, making them ideal candidates to save the world.

Launched last November, the vending machine-sized Dart – short for Double Asteroid Redirection Test – navigated to its target using new technology developed by the Johns Hopkins University Applied Physics Laboratory, the builder of the spacecraft and the mission manager.

Dart’s on-board camera, a key component of this intelligent navigation system, spotted Dimorphos just an hour before impact.

“Woo hoo,” exclaimed Adams, mission systems engineer at Johns Hopkins. « We see Dimorphos, so wonderful, wonderful. »

With an image beamed back to Earth every second, Adams and other ground controllers in Laurel, Maryland watched with growing excitement as Dimorphos loomed ever larger in the field of view alongside its larger companion. Within minutes, Dimorphos was alone in the photos; it looked like a giant gray lemon, but with rocks and rubble on the surface. The last image froze on the screen at the end of the radio transmission.

Flight controllers cheered, hugged and exchanged high fives. Their mission complete, Team Dart went straight into celebration mode. There was no grief over the disappearance of the spacecraft. “He meets his fate,” said Betsy Congdon, chief mechanical officer of Johns Hopkins.

A mini satellite followed a few minutes behind to take pictures of the impact. The Italian Cubesat came out of Dart two weeks ago.

The scientists insisted that Dart would not break Dimorphos. The spacecraft weighed just 1,260 pounds (570 kilograms), compared to 11 billion pounds (5 billion kilograms) for the asteroid. But that should be enough to reduce its orbit by 11 hours and 55 minutes around Didymos.

The impact should reduce that by 10 minutes, but the telescopes will need a few days to nearly a month to verify the new orbit. The projected 1% orbital shift might not seem like a lot, the scientists noted. But they stressed that this would represent a significant change over the years.

Planetary defense experts would rather fend off a threatening asteroid or comet, given enough time, than blow it up and create multiple chunks that could rain down on Earth. Multiple impactors might be needed for large space rocks or a combination of impactors and so-called gravity tractors, yet-to-be-invented devices that would use their own gravity to pull an asteroid into a safer orbit.

« The dinosaurs didn’t have a space program to help them know what was coming, but we did, » said NASA senior climate adviser Katherine Calvin, referring to the mass extinction there. is 66 million years old which would have been caused by a major asteroid impact. , volcanic eruptions or both.

The nonprofit B612 Foundation, dedicated to protecting Earth from asteroid strikes, has been pushing for impact testing like Dart since it was founded by astronauts and physicists 20 years ago. Monday’s feat aside, the world needs to do a better job of identifying the countless space rocks lurking there, warned the foundation’s executive director, Ed Lu, a former astronaut.

According to NASA, less than half of the estimated 25,000 near-Earth objects in the deadly range of 460 feet (140 meters) have been discovered. And less than 1% of the millions of smaller asteroids capable of widespread injury are known.

The Vera Rubin Observatory, nearing completion in Chile by the National Science Foundation and the U.S. Department of Energy, promises to revolutionize the field of asteroid discovery, Lu noted.

Finding and tracking asteroids, « That’s still the name of the game here. It’s the thing that has to happen to protect Earth, » 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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