The milestone comes courtesy of him Double Asteroid Redirect Test (DART) mission, which only started last fall. On September 26, DART will hit a small asteroid head-on, the rare occasion when destroying a spacecraft is the desired outcome. The mission is in the name of planetary defense, which it seeks to protect Earth from any asteroid impact; scientists hope it should be dangerous asteroid threaten the planet in the future, a mission like DART could prevent disaster. “These objects are launched into space, and of course they’ve scarred the moon and, over time, they’ve also had significant effects on Earth, they’ve affected our history,” Thomas Zurbuchen, NASA’s science associate, said during press conference held on Monday. (September 12). “A number of new missions that we’ve done are actually helping us understand and quantify these threats in an unprecedented way,” Zurbuchen added. “DART is a first mission that attempts to actually defeat a threat object in a direct experiment.” Scientists have identified and mapped the orbits of nearly 30,000 asteroids rattling around the solar system in Earth’s neighborhood. All of these space rocks either never intersect Earth or are so small that if they did, they would burn up harmlessly. earth’s atmosphere. However, it is possible that an asteroid impact in the future could damage Earth, and planetary defense experts want to be ready. The theory goes that if scientists ever spotted an asteroid on a collision course with Earth, an impactor could realign the space rock’s trajectory, ensuring it crossed Earth’s path when our planet was at a safe distance. But scientists don’t want to work only from theory if the situation arises. That’s where the dramatic DART disaster comes into play. The spacecraft will hit a small asteroid called Dimorphos, which is orbiting a larger near-Earth asteroid called Didymos every 11 hours and 55 minutes. (Neither asteroid poses a threat to Earth, and DART won’t change that.) DART’s impact should adjust Dimorphos’ orbit, cutting its orbit by perhaps 10 minutes. Scientists on Earth will spend weeks after the impact measuring the actual change in the moon’s orbit to compare with their predictions. The work will improve scientists’ understanding of how asteroids respond to impactors and help coordinate any future missions with the necessary amount of orbital change. “This is not just an isolated event,” Nancy Chabot, DART’s lead coordinator at Johns Hopkins University’s Applied Physics Laboratory in Maryland, which is running the mission, said during the news conference. “We want to know what happened to Dimorphos, but more importantly, we want to understand what this means for the possible application of this technique in the future.” While the stakes are low compared to any scenario that would motivate an actual asteroid diversion mission, the difficulty is the same. “This is incredibly challenging,” Evan Smith, the mission’s deputy system engineer, said during the press conference, noting that the spacecraft will be able to see Dimorphos itself about an hour and a half before impact. “This is a first lesson, so we’re going for success this time.” And if something doesn’t go according to plan? Mission personnel are pretty confident that, as long as the spacecraft hits its target, there should be something to see. “If DART collides with Dimorphos and then you don’t see any change in orbital period, that would be extremely surprising,” Chabot said. “Just the amount of momentum that DART alone brings from the weight of the spacecraft hitting Dimorphos is enough to shift its trajectory in a measurable way.” Missing the moon is still a possibility, but that’s what DART is all about: figuring out what would-be planetary defenders need to know if they ever want to launch a real asteroid diversion mission. “This will give all of us confidence that the diversion technology could work in the future,” Andrea Riley, a program officer at NASA who works with the agency’s Planetary Defense Coordination Office, said during the news conference. “If it misses, it still provides a lot of data. This is a test mission. That’s why we’re testing; we want to do it now and not when there’s a real need.” Email Meghan Bartels at [email protected] or follow her on Twitter @meghanbartels. Follow us on Twitter @Spacedotcom and up Facebook.
