The broadcast will start with scientific lectures at 8 p.m.
With New Horizons on autopilot, Mission Control was empty on Monday night at Johns Hopkins University's Applied Physics Laboratory in Laurel, Maryland.
The Queen guitarist, 71, is releasing New Horizons, his first solo work in over two decades, as a "tribute" to the spacecraft of the same name. Mission team members and New Horizons' fans, plus family members, noshed on hors d'oeuvres and watched presentations and performances (including a sing-along in New Horizons' honor) during the buildup to 12:33 a.m. ET (9:33 p.m. PT Dec. 31). To me, it epitomizes the human spirit's unceasing desire to understand the universe we inhabit.
But mission managers acknowledged that they didn't know exactly what New Horizons would send back.
"Ultima Thule means "beyond Thule" - beyond the borders of the known world - symbolizing the exploration of the distant Kuiper Belt and Kuiper Belt objects that New Horizons is performing, something never before done", the U.S. space agency said in a statement.
The exact shape and composition won't be known until Ultima Thule starts sending back data in a process expected to last nearly two years.
The rock will be the "most distant object ever visited by a spacecraft", according to NBC News.
'In effect, Ultima should be a valuable window into the early stages of planet formation and what the solar system was like over 4.5 billion years ago'.
Whether Ultima's surface is heavily cratered and if it has a rich surface geology - like that of Pluto - remains to be seen.
In fact, it takes more than six hours for radio signals carrying information from New Horizons to deliver the data to NASA's Deep Space Network.
The object was previously known as 2014 MU69.
Thule was a mythical island on medieval maps, thought to be the most northern point on Earth. He'll be debuting his new song "New Horizons" during the event.
Every 20 minutes, the spacecraft´s cameras and infrared imagers are capturing shots of the space rock, "so as it rotates and we get closer we will get good data on all parts of it as we approach", said John Spencer, a scientist with the Southwest Research Institute. As such, it is "probably the best time capsule we've ever had for understanding the birth of our solar system and the planets in it", Stern said. This region also is known as the "third zone" of our solar system, beyond the inner rocky planets and outer gas giants.
"Because this is a flyby, we only get one chance to get it right", Bowman said. "New Horizons is on the hunt to understand these objects, and we invite everyone to ring in the next year with the excitement of exploring the unknown".
The New Horizons team used the Hubble Space Telescope to search for the next Kuiper Belt object to fly by after Pluto. In 2017, scientists determined that it isn't spherical, but more elongated. Astronomers believe it is a contact binary, comprising two objects touching each other, or perhaps even a binary system, in which two objects are orbiting one another.
'Because of where it was formed and the fact that Ultima is not large enough to have a geologic engine like Pluto and larger planets, we expect that Ultima is the most well-preserved sample of a planetary building block ever explored.