NASA called in New Year on Tuesday with a historic aerodrome of the farthest and possibly the oldest cosmic body ever explored by mankind – a small distant world called Ultima Thule – hoping to learn more about how planets took shape.
"Go New Horizons!" said senior researcher Alan Stern as a crowd, including children dressed in room costumes blew fest horns and cheered at the Johns Hopkins Applied Physics Laboratory in Maryland to mark the moment at 12:33 pm (4:33 pm AEDT), as New Horizon's spacecraft is aiming cameras in space rock 6.4 billion kilometers away in a dark and frigid area of space known as the Kuiper Belt.
Offering scientists the first perceptive look at an ancient site of planets, the aerodrome took place about a billion miles beyond Pluto, which until now was the farthest world ever visited near a spacecraft.
Real-time video of the actual airfield was impossible as it took more than six hours for a signal sent from Earth to reach the spacecraft, and another six hours for the response to arrive.
The first signal back to Earth was to come about 10 hours after flyby at 9:45 am (1:45 AM AEDT, Wednesday), so NASA knows if New Horizons survived the risky, fast-paced meeting.
Hurtling through space at a speed of 32,000 miles per hour, the spacecraft aimed to make its closest approach within 2,200 miles of the surface of the Ultima Thule.
"This is one evening, neither of us will forget," said Queen's guitarist Brian May – who also has an advanced degree in astrophysics – who recorded a solo track to honor the spacecraft and its exploration spirit.
Stern said Ultima Thule is unique because it is a relic from the early days of the solar system and could provide answers about the origin of other planets.
"The object is in such a deep freeze that it is perfectly preserved from its original formation," he said.
"Everything we need to learn about Ultima – from its composition to its geology to how it was originally assembled, whether it has satellites and an atmosphere and those kinds of things – must teach us about the original formation conditions of objects in the solar system."
How does it look?
Scientists are not sure what Ultima Thule (pronounced TOO-lee) looks like – whether it is cratered or smooth, or even a single object or cluster.
It was discovered in 2014 using the Hubble Space Telescope, and it is believed to be 12-20 miles in size.
A blurry and pixelated image released Monday, taken from 1.2 million miles away, has fascinated scientists because it appears to be an elongated flower, not a round space rock.
The spacecraft was supposed to collect 900 images in seconds as it shaved off. Even clearer images must arrive within the next three days.
"Now it's just a matter of time to see the data coming down," said Deputy Researcher John Spencer of the Southwest Research Institute.
The researchers decided to study Ultima Thule with New Horizons, after the spacecraft launched in 2006 completed its main mission to fly by Pluto in 2015, and returned the most detailed images ever taken by the dwarf planet.
Stern said the goal is to take pictures of Ultima, which is three times the resolution that the team had for Pluto.
The limit of the planetary science
Ultima Thule is named after a mythical, far north island in medieval literature and cartography, according to NASA.
Project researcher Hal Weaver from Johns Hopkins Applied Physics Laboratory said that humans did not even know the Kuiper Belt – a large ring of relics from the solar system's formation days – existed until the 1990s.
"This is the limit of planetary science," Weaver said.
"We've finally reached the edge of the solar system, these things that have been there since its inception and hardly changed – we believe. We'll find out."
Another NASA spacecraft, OSIRIS-REX, also set a new record on Monday by entering circuits around the asteroid Bennu, the smallest cosmic object – about 1600 feet (500 meters) in diameter – ever circulated by a spacecraft.
NASA said the round about 110 million miles marks "a leap of humanity" because no spacecraft has ever "circled so close to such a small space object – one with barely enough gravity to hold a vehicle in a stable path."
The two planetary celebrations coincided with the 50th anniversary of the first time humans ever explored another world when American astronauts surrounded the moon aboard Apollo 8 in December 1968.
"As you celebrate New Year's Day, throw an eye up and think for a moment about the amazing things our country and our species can do when we set our minds on it," wrote Stern in the New York Times Monday.