“This inaugural planetary defense test mission marks a major moment in human history,” Bobby Braun, head of APL’s space exploration sector, said during a pre-impact briefing on September 12. And in 2026, a spacecraft called Hera built by the European Space Agency (ESA), will arrive to monitor the collision’s aftermath. More than three dozen ground-based telescopes will now get to work making precise measurements of the moonlet’s new orbit. The goal of these observations is to look for any hints of brightening in the Didymos system, which will provide crucial information about how much dust and pulverized rock the impact kicked up. Pacific Time on a SpaceX Falcon 9 rocket from Vandenberg Space Force Base in California. Right: DART, the world’s first mission to test technology for defending Earth against potential asteroid or comet hazards, launches on November 23, 2021, at 10:21 p.m. NASA’s James Webb Space Telescope and Hubble Space Telescope were also trained on the Didymos system at the moment of impact, and Lucy, a spacecraft on its way to a strange population of asteroids that orbit near Jupiter, was close enough to observe the impact as well. Over the next few days, the little spacecraft will beam images of the crash site back to Earth, where scientists will study them to learn more about the structure and composition of Dimorphos. Three minutes after the collision, a cubesat called LICIACube arrived to surveil the wreckage. Making sure this strategy works will require some careful follow-up observations, and an impressive array of instruments have swiveled to monitor the Didymos system. It was more of a flick-a nudge that packed enough of a punch to change the moonlet’s orbit without smashing it into pieces. But unlike movie plots to blow up asteroids before they hit the planet, the DART impact wasn’t an attempt to obliterate Dimorphos. The collision resembles the desperate, last-minute attempts to save Earth from cosmic annihilation in Hollywood blockbusters. Teams recently named the space rock Dimorphos, which is Greek for “having two forms”-one before the impact, and one after. But no one had ever gotten a good look at its tiny moonlet until just before DART smashed into it. As it approached, the spacecraft furiously snapped images of Dimorphos, which rapidly grew from a pinprick of light to fill its field of view-until the moment of impact, when everything went dark.ĭimorphos orbits a larger asteroid called Didymos, and the two asteroids are not considered threats to Earth-which is one of the reasons NASA put them in the DART spacecraft’s crosshairs for this first planetary defense test.ĭiscovered in 1996, Didymos, which means “twin” in Greek, is roughly a half-mile across and relatively well studied. To practice shaping that reality, NASA sent DART hurtling toward its demise. “This is just the first step, but isn’t it exciting that we’re going from science fiction to science reality?” “I don’t really lose sleep about the Earth getting destroyed by asteroids, but I am excited about living in a world where we might be able to potentially prevent this in the future,” says Nancy Chabot of Johns Hopkins University’s Applied Physics Laboratory (APL) in Laurel, Maryland, which manages the DART mission. And eventually, whether in hundreds or thousands or millions of years, it is all but certain that life on Earth will face an existential threat from an asteroid. While scientists are confident that a large enough asteroid to cause planet-wide extinction will not threaten Earth for at least a hundred years-after which time it is difficult to predict their orbits-it is still possible that we could be surprised by a smaller, potentially city-destroying rock from space. It's also the first test of a bold strategy that could be used to deflect any future asteroids that are on a collision course with Earth. ET, marks the first time humans have intentionally changed the course of a celestial object. The collision between NASA’s Double Asteroid Redirection Test (DART) spacecraft and a 500-foot-wide rock called Dimorphos, which took place at 7:14 p.m. Laurel, MarylandNearly seven million miles from Earth, a spacecraft traveling more than 14,000 miles an hour smashed into a small, unsuspecting asteroid that had been floating through space undisturbed for eons.
0 Comments
Leave a Reply. |