Watch: NASA spacecraft slams into asteroid in defense test
A NASA spacecraft rammed an asteroid at blistering speed Monday in an unprecedented dress rehearsal for the day a killer rock menaces Earth.
The galactic grand slam occurred at a harmless asteroid 7 million miles away, with the spacecraft named Dart plowing into the small space rock at 14,000 mph. Scientists expected the impact to carve out a crater, hurl streams of rocks and dirt into space and, most importantly, alter the asteroid鈥檚 orbit.
Watch the video above to see the spacecraft's collision with the asteroid.
Telescopes around the world and in space aimed at the same point in the sky to capture the spectacle. Though the impact was immediately obvious 鈥� Dart鈥檚 radio signal abruptly ceased 鈥� it will be days or even weeks to determine how much the asteroid鈥檚 path was changed.
was the first attempt to shift the position of an asteroid or any other natural object in space.
鈥淣o, this is not a movie plot,鈥� NASA Administrator Bill Nelson tweeted earlier in the day. 鈥漌e鈥檝e all seen it on movies like 鈥楢rmageddon,鈥� but the real-life stakes are high,鈥� he said in a prerecorded video.
Monday鈥檚 target: a 525-foot asteroid named Dimorphos. It鈥檚 actually a moonlet of Didymos, Greek for twin, a fast-spinning asteroid five times bigger that flung off the material that formed the junior partner.
The pair have been orbiting the sun for eons without threatening Earth, making them ideal save-the-world test candidates.
Launched last November, the vending machine-size Dart 鈥� short for Double Asteroid Redirection Test 鈥� navigated to its target using new technology developed by Johns Hopkins University鈥檚 Applied Physics Laboratory, the spacecraft builder and mission manager.
Dart鈥檚 on-board camera, a key part of this smart navigation system, caught sight of Dimorphos barely an hour before impact.
鈥淲oo hoo,鈥� exclaimed Johns Hopkins mission systems engineer Elena Adams. "We鈥檙e seeing Dimorphos, so wonderful, wonderful.鈥�
With an image beaming back to Earth every second, Adams and other ground controllers in Laurel, Maryland, watched with growing excitement as Dimorphos loomed larger and larger in the field of view alongside its bigger companion.
A mini satellite followed a few minutes behind to take photos of the impact. The Italian Cubesat was released from Dart two weeks ago.
Scientists insisted Dart would not shatter Dimorphos. The spacecraft packed a scant 1,260 pounds, compared with the asteroid鈥檚 11 billion pounds. But that should be plenty to shrink its 11-hour, 55-minute orbit around Didymos.
The impact should pare 10 minutes off that, but telescopes will need anywhere from a few days to nearly a month to verify the new orbit. The anticipated orbital shift of 1% might not sound like much, scientists noted. But they stressed it would amount to a significant change over years.
Planetary defense experts prefer nudging a threatening asteroid or comet out of the way, given enough lead time, rather than blowing it up and creating multiple pieces that could rain down on Earth. Multiple impactors might be needed for big space rocks or a combination of impactors and so-called gravity tractors, not-yet-invented devices that would use their own gravity to pull an asteroid into a safer orbit.
鈥淭he dinosaurs didn鈥檛 have a space program to help them know what was coming, but we do,鈥� NASA鈥檚 senior climate adviser Katherine Calvin said, referring to the mass extinction 66 million years ago believed to have been caused by a major asteroid impact, volcanic eruptions or both.
The non-profit B612 Foundation, dedicated to protecting Earth from asteroid strikes, has been pushing for impact tests like Dart since its founding by astronauts and physicists 20 years ago. Monday鈥檚 feat aside, the world must do a better job of identifying the countless space rocks lurking out there, warned the foundation鈥檚 executive director, Ed Lu, a former astronaut.
Significantly less than half of the estimated 25,000 near-Earth objects in the deadly 460-foot range have been discovered, according to NASA. And fewer than 1% of the millions of smaller asteroids, capable of widespread injuries, are known.
The Vera Rubin Observatory, nearing completion in Chile by the National Science Foundation and U.S. Energy Department, promises to revolutionize the field of asteroid discovery, Lu noted.
Finding and tracking asteroids, 鈥淭hat鈥檚 still the name of the game here. That鈥檚 the thing that has to happen in order to protect the Earth,鈥� he said.
