The impact should shorten that time period, but scientists don't know by how many minutes.Īdams says that telescopes will be watching closely in the weeks and months after the impact to "see how does it react to being pushed."Ī tiny satellite jettisoned from the spacecraft 10 days before the impact should send back images of the collision itself and the resulting blast of debris. Right now, Dimorphos goes around every 11 hours and 55 minutes. In fact, this pair of asteroids is so small and far away that telescopes see them as little more than a point of light.Ĭhanges in brightness, however, tell scientists when the orbiting Dimorphos passes in front of its companion. No one knows what shape this asteroid has or whether its surface is smooth or rugged. ![]() Images sent back by the doomed spacecraft in the last seconds before the crash will give scientists their first good look at Dimorphos. Then, in the final hour or so, it will detect the smaller one and switch to that target. Initially, the spacecraft will orient itself by aiming for the larger asteroid, explains Adams. "It is four hours of watching paint dry, but kind of terrifying at the same time because the spacecraft is completely autonomous," says Elena Adams, the mission systems engineer at the Johns Hopkins University Applied Physics Laboratory. In the last few hours of the mission, managers back on Earth will only be able to watch as the spacecraft flies itself and homes in on its target. "So it's like a small golf cart running into a Great Pyramid," says Chabot - only this "golf cart" will be going 15,000 miles per hour. It's the small asteroid, Dimorphos, that will get smacked by the spacecraft. This asteroid is orbited by a smaller asteroid called Dimorphos, which is about 525 feet across. "There is absolutely no way that the DART test is a threat to the Earth," she says.Īfter the DART spacecraft launches, it will spend about 10 months traveling out toward an asteroid called Didymos, which is about 2,500 feet across. The asteroid targeted by DART isn't a danger to the planet now, and Chabot says there's no chance this mission could make it one. It is absolutely not asteroid disruption, which is how it goes a lot of times in the movies," says Chabot, who serves as DART's coordination lead. ![]() "DART is demonstrating asteroid deflection. That's the approach that NASA is testing out with DART. With enough advance warning, NASA could send out a spacecraft that would simply give an asteroid a little push, changing its course so that it no longer posed a problem. NASA/Johns Hopkins APL/Ed Whitman In a clean room at Johns Hopkins APL, NASA's DART spacecraft is moved into a specialized shipping container bound for its launch site at Vandenberg Space Force Base in California. "The strategy is to find these objects not only years but decades before they are any kind of an impact hazard to the Earth." "The right time to deflect an asteroid is as far away from the Earth as we can," says Lindley Johnson, NASA's planetary defense officer. In reality, messy and unpredictable nuclear weapons aren't the preferred choice of planetary defense experts, who would much rather identify dangerous space rocks way in advance of any possible collision and use more controlled methods to alter its path. Movies like Armageddon or Meteor typically feature a surprise, imminent killer asteroid, and saving humanity invariably requires blowing it to pieces with a nuclear bomb. "A lot of times when I tell people that NASA is actually doing this mission, they kind of don't believe it at first, maybe because it has been the thing of movies," says Nancy Chabot, a planetary scientist at the Johns Hopkins University Applied Physics Laboratory. It might sound like a movie plot, but it's not ![]() It's a space rock of that smaller size that the DART mission - short for Double Asteroid Redirection Test - will take head-on. But there are plenty of smaller asteroids, the size that could take out a city, that still haven't been found and tracked. For the foreseeable future, none that big are headed our way. NASA has identified and tracked almost all of the nearby asteroids of a size that would cause world-altering damage if they ever struck Earth. Scientists will then watch to see how the asteroid's trajectory changes. The golf-cart-size spacecraft will travel to an asteroid that's more than 6 million miles away - and poses no danger to Earth - and ram into it. In the first real-world test of a technique that could someday be used to protect Earth from a threatening space rock, a spacecraft is scheduled to blast off from Vandenberg Space Force Base in California on Tuesday at 10:20 p.m. NASA is about to launch an unprecedented mission to knock an asteroid slightly off course.
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