A NASA spacecraft touched an asteroid Tuesday, a first for the space agency and the United States. The Osiris-Rex dodged gigantic orbiting boulders after traveling more than 200 million miles to reach down to Bennu with a robotic arm and extract materials from its surface for study back on Earth. The gravity of the asteroid was too weak for the craft to touch down on the surface. “I can't believe we actually pulled this off. The spacecraft did everything it was supposed to do,” said the University of Arizona’s Dante Lauretta, the lead scientist on the mission. Scientists chose Bennu because they believe it holds geological clues to the evolution of earth and the solar system. Thomas Zurbuchen, NASA’s science mission chief, called the asteroid “something that’s out there and tells the history of our entire Earth, of the solar system, during the last billions of years.” The spacecraft launched from Cape Canavral, Florida in 2016, orbited its target for nearly two years, and is scheduled to complete its return journey in 2023.