![]() So as a target for celestial skeet-shooting it served its purpose well. “The key point of this type of technique is to just give that little nudge such that the asteroid crosses over Earth’s path, either just before we get there or just after we’ve gone by,” said Nancy Chabot, DART science coordinator at the Johns Hopkins Applied Physics Laboratory in Laurel, Md.īut Dimorphos is both a harmless and relatively static object-a known rock that keeps its distance at a known spot in space, never venturing anywhere near Earth. The DART impact was intended as a test of the kind of deflection technology that might one day be necessary to save Earth from just such a killer rock. Neither Dimorphos nor Didymos pose any danger to Earth, but other asteroids out there do pose a potential collision risk to our planet. ![]() The purpose of the cosmic collision? To see if DART’s impact could nudge Dimorphos, speeding it up slightly and shortening its orbit around Didymos. Dimorphos is a moonlet of the larger, 780 m (2,560 ft) asteroid Didymos, making one revolution around its parent rock every 11 hours and 55 minutes. The spacecraft, known as DART (for Double Asteroid Redirection Test), was launched last November, and its sole job was to fly out to the small, 160 m (525 ft.) asteroid Dimorphos, and crash into it at at 22,500 k/h (14,000 mph). And we should all be very glad they did, because today the Earth feels a little bit safer than it did yesterday. “The dinosaurs didn’t have a space program to help them know what was coming, but we do,” NASA’s 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 mission managers at NASA spent $330 million to send a refrigerator-sized spacecraft 7 million miles (11 million km) into space and punch an asteroid in the nose. 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. ![]() 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. But they stressed it would amount to a significant change over years. The anticipated orbital shift of 1% might not sound like much, scientists noted. 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. But that should be plenty to shrink its 11-hour, 55-minute orbit around Didymos. The spacecraft packed a scant 1,260 pounds, compared with the asteroid’s 11 billion pounds. Scientists insisted Dart would not shatter Dimorphos. The Italian Cubesat was released from Dart two weeks ago. 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.Ī mini satellite followed a few minutes behind to take photos of the impact. “We’re seeing Dimorphos, so wonderful, wonderful.” “Woo hoo,” exclaimed Johns Hopkins mission systems engineer Elena Adams. Launched last November, the vending machine-size Dart - short for Double Asteroid Redirection Test - navigated to its target using new technology developed by Johns Hopkins University’s Applied Physics Laboratory, the spacecraft builder and mission manager.ĭart’s on-board camera, a key part of this smart navigation system, caught sight of Dimorphos barely an hour before impact. The pair have been orbiting the sun for eons without threatening Earth, making them ideal save-the-world test candidates. It’s 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. Monday’s target: a 525-foot asteroid named Dimorphos. ”We’ve all seen it on movies like ‘Armageddon,’ but the real-life stakes are high,” he said in a prerecorded video. “No, this is not a movie plot,” NASA Administrator Bill Nelson tweeted earlier in the day. ![]() The $325 million mission was the first attempt to shift the position of an asteroid or any other natural object in space. ![]()
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