Lead scientist Alan Stern of Southwest Research Institute in Boulder, Colorado, expects the New Year's encounter to be riskier and more hard than the rendezvous with Pluto: The spacecraft is older, the target is smaller, the flyby is closer and the distance from us is greater. At the Johns Hopkins University Applied Physics Laboratory, which built and operates the spacecraft, scientists will count down to the moment of New Horizons' closest approach, at 12:33 a.m.
Queen guitarist Brian May, who also happens to be an astrophysicist, joined the team at Johns Hopkins for a midnight premiere of the song he wrote for the big event.
If New Horizons sounds familiar, it's because this is the spacecraft that conducted a historic flyby of Pluto in 2015, sending back unprecedented images of the dwarf planet and revealing new details about Pluto and its moons.
"This is history making what we're doing, in more ways than one, " Stern said.
"The object is in such a deep freeze that it is perfectly preserved from its original formation", he said. "We are ready for Ultima science transmission, science to help us understand the origins of our solar system".
What does it look like?.
Scientists say there are two possibilities for this: Ultima Thule is either one object with two connected lobes, sort of like a spinning bowling pin or peanut still in the shell, or two objects orbiting surprisingly close to one another.
A blurred and pixelated image released Monday, taken from 1.9 million km away, has intrigued scientists because it appears to show an elongated blob, not a round space rock.
The spaceship was to collect 900 images over the course of a few seconds as it shaved by.
"This is just raw exploration", said Alan Stern, a scientist at the Southwest Research Institute and the principal investigator for the mission.
A visualization of the New Horizons spacecraft flying by Ultima Thule on New Year's Day.
An image of Thule, sent overnight and barely more detailed than previous images, deepens the mystery of whether Thule is a single rock shaped like an asymmetrical peanut or actually two rocks orbiting each other, "blurred together due to their proximity", Stern said.
The US space agency is ringing in the New Year with a live online broadcast to mark New Horizons' zoom past the mysterious object located about four billion miles away in a dark and frigid region of space known as the Kuiper Belt.
"This is the frontier of planetary science", said Weaver.
It is the furthest exploration of any object in the Solar System. "We will find out".
The spacecraft encountered the object previously known as 2014 MU69 approximately three and a half years after brushing past Pluto, previously the most distant object ever explored.
After months of staring at only a single pixel of their target, members of NASA's New Horizons mission team now have considerably more to look at.
The nerdiest New Year's party in the solar system is happening 4billion miles from Earth, where a lone, intrepid explorer is en route to the furthest object humans have ever explored.
When the probe was launched in 2006 it had two goals.