Channel: NOVA PBS Official

Category: Science & Technology

Tags: pbsnasa asteroid missionnasa planetary defensenasa planetary defense coordination officedart missionasteroidspacecraftasteroid impactspacecraft missionextinction eventmeteoriteplanetary defensenovanasa dartdinosaur extinction eventnasa missionchelyabinsk meteormeteordeflecting asteroidstunguska eventmeteor strikedinosaur extinctionnasaspace missionplanetary defense coordination officeplanetary defense coordinationchelyabinsk

Description: NASA’s new spacecraft mission DART will test scientists’ ability to deflect asteroids at risk of colliding with Earth and is scheduled to launch later this year, NASA wrote in an April press release. “An impact on Earth doesn’t happen very often—that doesn’t mean they don’t happen,” University of Colorado aerospace engineer Paul Sanchez told NOVA. “This isn't the sort of thing that we want to address at the last minute,” NASA Planetary Defense Coordination Office scientist Kelly Fast added. Sixty-six million years ago, a miles-wide asteroid crashed into Earth, wiping out three-quarters of the world’s plant and animal species, including all non-avian dinosaurs. (The occurrence is now known as the Cretaceous-Paleogene, or K-Pg, event.) And on Jun. 30, 1908, an asteroid streaked over the Siberian sky and exploded, flattening about 80 million trees over an area of 830 square miles of forest and, according to eyewitnesses, killing at least three people. Called the Tunguska event, it’s the most harmful known asteroid-related incident on Earth in recent history. Today, Space agencies including NASA are confident they’re tracking asteroids big enough to cause a major extinction event. Fortunately, none are headed our way in the foreseeable future. But following asteroids—and learning how to redirect them away from Earth—is important, NASA’s Planetary Defense Coordination Office, which was founded in 2016, believes. Watch to discover how the Planetary Defense team is taking on this challenge. PRODUCTION CREDITS: Produced by: Angelica Coleman Caitlin Saks Production Assistance: Lorena Lyon Christina Monnen Animation: Edgeworx Studios Ed Bell Media Unit TV & Film Archival: Storyblocks NASA/JPL-Caltech NASA/Johns Hopkins APL NASA/Johns Hopkins APL/Lee Hobson NASA/Johns Hopkins APL/Steve Gribben Music: APM © WGBH Educational Foundation 2021