On September 26, NASA will crash into an asteroid spacecraft to disrupt its path. A space rock is not expected to collide with Earth, and nothing else is known asteroid or a large object. Impact Test – Core of NASA’s Double Asteroid Redirection Test (Arrow) Expedition. Although there is no real imminent collision, the DART mission closely simulates what NASA scientists would do if an asteroid were headed toward Earth. The mission will also provide scientists with valuable data that will better prepare them to redirect a large asteroid or comet If one has to turn towards us.
“It’s exactly the kind of mission we’re actually going to use to deflect the asteroid,” Seth Jacobson, associate professor of planetary sciences at Michigan State University and a co-investigator on the mission, told Space.com.
The DART mission is specifically testing a method called kinematic deflecting technology – essentially smashing a spacecraft into an asteroid to try to divert or redirect it away from a land. Its target is the small moon Dimorphos, which orbits the larger asteroid Didymus. It’s 525 feet (160 meters) in diameter, which is exactly the size of an asteroid that scientists would really try to redirect with a kinetic collider, Jacobson said, since the asteroid would be large enough that simple evacuation procedures would not be practical. , but small enough that a moving object on its own can deflect it. He said the strategy would be particularly useful if we discovered the effect less than a few decades before it occurred.
Related: NASA’s DART asteroid impact mission will be a major test of planetary defense
Although an object the size of Dimorphos could cause severe damage if it collided with Earth, it likely would not pose a danger to the entire planet. For comparison, an asteroid Chicxulub, which caused the extinction of non-floating dinosaurs, was about 6 miles (10 km) in diameter. In order to disperse anything close to this size, Jacobson said, we would need a nuclear bomb or other powerful explosive connected to the kinetic collider. We would also need a lot of time, ideally several decades, to develop such a missile, he said. But even with such a large object, the basic idea is the same as the idea behind DART: transmit momentum to the object by smashing something into it and redirecting it.
“We really need to understand this technology first, before you can imagine adding an explosive component,” Jacobson said.
The mission also demonstrates the high level of international cooperation needed to plan and execute a near-Earth object kinetic impact. Although the mission is led by NASA and the Johns Hopkins University Applied Physics Laboratory, scientists and engineers from around the world are contributing to DART — for example, by calculating Dimorphos’ exact orbit around Didymos and measuring the success of the mission.
“We’ve worked closely with our European colleagues and our colleagues around the world,” Elaine Howell, a senior researcher at the University of Arizona’s Lunar and Planetary Laboratory and a DART associate investigator, told Space.com. Although DART is a test, a similar level of international cooperation would be necessary if there was a real impact, she said.
Of course, there are some key differences between DART and defense against a real asteroid impact. The biggest one is that no asteroid in the chosen system is expected to hit Earth. Scientists chose Didymus because it is called an ecliptic binary when viewed from Earth – in other words, Demorphos clearly passes in front of Didymus, making it dim. This dimming allows scientists to accurately measure how long it takes a smaller asteroid to orbit a larger asteroid and how much that time period will change once the DART spacecraft collides with Dimorphos. Jacobson said that scientists will use this information to work out how much momentum the spacecraft is transmitting to the asteroid, information that will be important if we really need to use this technology.
In addition, the real target would certainly not be part of a binary system, Hoyle said, because very few asteroids exist. In addition, the risk of any object of this size or larger impacting the Earth in the near future is very small. NASA says There is nothing to worry about, at least for the next century.
However, NASA’s Planetary Defense Coordination Office takes the risks of NEO impact seriously — the same way many people study and try to mitigate the effects of earthquakes, tsunamis, and volcanic eruptions, Jacobson said.
“These are all things that pose natural risks,” he said. “While you can never completely eliminate the possibility of it happening, you can certainly mitigate its impact and try to avoid the worst case scenario.”
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