After a two-year chase, a NASA spacecraft arrived Monday at the ancient asteroid Bennu, its first visitor in billions of years.
The robotic explorer Osiris-Rex pulled within 12 miles (19 kilometers) of the diamond-shaped space rock.
It will get even closer in the days ahead and go into orbit around Bennu on Dec. 31. No spacecraft has ever orbited such a small cosmic body.
It is the first U.S. attempt to gather asteroid samples for return to Earth, something only Japan has accomplished so far.
Flight controllers applauded and exchanged high-fives once confirmation came through that Osiris-Rex made it to Bennu - exactly one week after NASA landed a spacecraft on Mars.
"Relieved, proud, and anxious to start exploring!" tweeted lead scientist Dante Lauretta of the University of Arizona.
"To Bennu and back!"
With Bennu some 76 million miles (122 million kilometers) away, it took seven minutes for word to get from the spacecraft to flight controllers at Lockheed Martin in Littleton, Colorado.
The company built the spacecraft there.
Bennu is estimated to be just over 1,600 feet (500 meters) across.
Researchers will provide a more precise description at a scientific meeting next Monday in Washington.
About the size of an SUV, the spacecraft will shadow the asteroid for a year, before scooping up some gravel for return to Earth in 2023.
Scientists are eager to study material from a carbon-rich asteroid like dark Bennu, which could hold evidence dating back to the beginning of our solar system 4.5 billion years ago. As such, it's an astronomical time capsule.