STORY: "Looks to me like we're headed straight in."Can mankind deflect an asteroid on a collision course with Earth? NASA has inched one step closer to finding out.After its DART spacecraft successfully slammed into a distant asteroid at hypersonic speed.DART, or the Double Asteroid Redirection Test, is the world's first-ever test of a planetary defense system. Humanity's first attempt to alter the motion of an asteroid or any celestial body."3...2...1..."NASA workers just outside Washington D.C. cheered as they witnessed the bullseye hit.Second-by-second images of the spacecraft crashing into the asteroid 'moonlet' known as Dimorphos, ten months after DART first launched."We have impact." The mission was devised to determine whether a spacecraft can nudge an asteroid off course through sheer kinetic force.Even just a small tilt from millions of miles away and years in advance could potentially keep our planet out of harm's way. Nancy Chabot is the DART mission's Coordination Lead. "The test went spectacularly. It was really everything that we expected, and even, honestly, more. We were sitting there watching these images come in as we got closer and closer to Dimorphos, saw those surface features, and they came into focus. I think all of us had said it would be spectacular - and it was."But while NASA's spacecraft successfully hit its intended target, whether it did anything to change its trajectory will not be known until further observations in October. Elena Adams is one of the mission's engineers. "That's our number two goal. Number one was hit the asteroid, which we've done. But now number two is really measure that period change and characterize how much ejecta we actually put out." Neither Dimorphos or its parent asteroid Didymos present any actual threat to Earth. Both are tiny compared with the cataclysmic Chicxulub asteroid that struck Earth some 66 million years ago, wiping out about three-quarters of the world's plant and animal species including the dinosaurs.Of all the near-Earth asteroids that NASA tracks, none are known to pose a foreseeable hazard.However, NASA estimates there are many more near-Earth asteroids that remain undetected.