Dec. 31 (UPI) -- NASA's New Horizons probe rang in the new year by swinging by Ultima Thule, a small object in the Kuiper asteroid belt.
The spacecraft passed within 2,200 miles of the large asteroid at 12:33 a.m. EST Tuesday, not long after the ball dropped in New York Times Square. The close encounter marks the farthest spacecraft flyby in history.
The New Horizons is approximately 4 billion miles from the sun. Because of the long distance from Earth, scientists didn't know how the flyby went until several hours after the rendezvous.
At 10:29 a.m., flight controllers at Johns Hopkins University's Applied Physics Laboratory in Laurel, Md., received word from the spacecraft. Those in the mission control and a spill-over crowd in a nearby auditorium cheered upon the "phone home" communication.
"We have a healthy spacecraft," Alice Bowman, mission operations manager for New Horizons, said after signal notification. "We've just accomplished the most distant flyby. We are ready for Ultima Thule science transmission."
At 11:30 a.m., scientists involved with the New Horizons mission released the first images and data returned by the spacecraft.
"New Horizons performed as planned today, conducting the farthest exploration of any world in history - 4 billion miles from the sun," said Principal Investigator Alan Stern, of the Southwest Research Institute in Boulder, Colo. "The data we have looks fantastic and we're already learning about Ultima from up close. From here out, the data will just get better and better!"
Before the data transmission, Stern marveled at the achievement.
"We set a record! Never before has a spacecraft explored something so far away," he said. "I mean, think of it. We're a billion miles further than Pluto, and now we're going to keep going into the Kuiper Belt."
On Monday, he told reporters during a news briefing "I'd be kidding you if I didn't tell you we're also on pins and needles to see how this turns out."
Ultima Thule, or 2014 MU69, lies beyond the orbits of Neptune and Pluto, in the outer realms of the solar system. The space rock features a diameter of roughly 19 miles. Its irregular shape recalls two rock smashed together, like a snowman without a head.
New Horizons first launched in 2006 with the goal of doing a flyby study of the Pluto system by 2015. The probe gathered its last Pluto observations in 2016 and began making its way toward the Kuiper Belt.
Based on images taken during the spacecraft's approach, the Kuiper Belt is approximately 20 by 10 miles shaped similar to a bowling pin and spinning end over end. It's possible, Ultima is in fact two objects orbiting each other.
Scientists think the clarity of the images captured during the Ultima Thule flyby could rival the photographs taken during New Horizon's close encounter with Pluto.
Researchers are interested in small objects in the far reaches of the solar system, asteroids and comets, because they could contain clues to the solar system's origin story.
"Asteroids, comets and other small bodies hold material from the solar system's birth. If we want to know where we come from, we must study these objects," said Lori Glaze, acting director for the Planetary Science Division at NASA Headquarters.
The New Horizons spacecraft is expected to be downloading images and other data for the next several months.
"Congratulations to NASA's New Horizons team, Johns Hopkins Applied Physics Laboratory and the Southwest Research Institute for making history yet again," NASA Administrator Jim Bridenstine said. "In addition to being the first to explore Pluto, today New Horizons flew by the most distant object ever visited by a spacecraft and became the first to directly explore an object that holds remnants from the birth of our solar system. This is what leadership in space exploration is all about."