On Sept. 24, NASA's OSIRIS-REx spacecraft will come hurtling through Earth's atmosphere, carrying samples of the nearby, "potentially hazardous" asteroid Bennu.
The return is the climax of a seven-year flight — beginning with the spacecraft's 2016 launch — that was the first U.S. mission to collect a sample from an asteroid. Once analyzed, the sample promises to yield vital details about how life in the solar system began and about the movement of an asteroid that could one day crash violently into Earth.
