Osiris-Rex used Earth’s gravity as a slingshot to put it on a path toward the asteroid Bennu.
NASA’s asteroid-chasing spacecraft swung by Earth on its way to a space rock.
Launched a year ago, Osiris-Rex passed within 17,237 kilometres of the home planet early Friday afternoon above Antarctica. It used Earth’s gravity as a slingshot to put it on a path toward the asteroid Bennu.
Osiris-Rex should reach the small, roundish asteroid next year and, in 2020, collect some of its gravel for the return to Earth. If all goes well, scientists should get the samples in 2023.
Bennu is just 500 meters or so across and circles the sun in an orbit slightly wider than ours. Osiris-Rex will go into orbit around the asteroid and seek the best spot for grabbing a few handfuls of the bite-size bits of rock. It will hover like a hummingbird as a mechanical arm briefly rests on the surface and sucks in samples stirred up by nitrogen gas thrusters.
Scientists say the ancient asteroid could hold clues to the origin of life. It’s believed to have formed 4.5 billion years ago, a remnant of the solar system’s building blocks.
This is the first U.S. attempt to bring back samples from an asteroid. Japan already has visited an asteroid and returned some specks.