To ancient explorers, "ultima Thule" or the most remote region, it was beyond the northernmost edges of maps, beyond the boundaries of the known world.
So when NASA chose a target for its New Horizon spacecraft It was longer than previously investigated, Ultima Thule seemed a fitting moniker. The remote space stone is a resident of the Kuiper Belt, the ring of debris surrounding the sun's icy outer stretches.
Ultima Thule is so dim and so remote that scientists do not even know what it looks like. Some of their only information about its size and shape comes from coordinated observations last summer when astronomers measured the shadow cast as it passed in front of a star.
New horizons will finally fly after their goal shortly after midnight on January 1
"This is just an investigation," said Alan Stern, a researcher at the Southwest Research Institute and the principal investigator for the mission.
"No one has ever seen a Kuiper belt object as anything but a point of light. No one has ever seen an object frozen almost to absolutely zero. There are many ideas and all of them may be wrong."
He took his breath. "We're going to find out Tuesday."
NASA celebrates the record-breaking meeting on what is perhaps the second-year New Year's party of the solar system.
At the Johns Hopkins University Applied Physics Laboratory (APL), which built and operates the spacecraft, scientists will count down to the moment New Horizon's closest approach is, at 12:33 Eastern Time (05:33 UTC) Recuperate 10 hours later to watch the first signals from the flyby stream on their screens. (It takes more than six hours for light to travel from Ultima Thule to Earth.)
NASA's charity social media operation an accident for partial government closure, has been temporarily restored to cover the event. The countdown, signaling and subsequent news conferences will be streaming live on NASA TV and YouTube.
Alice Bowman, New Horizons Mission Operations Manager at APL, said the spacecraft entered "meeting" on Wednesday. This configuration restricts spacecraft communication with the earth and orders it to address any technical issues quickly, and then returns to science.
Although network management for engineers ensures the meeting mode that New Horizons gets most of its short time near Ultima Thule.
"Because this is a flyby, we only get a chance to get it right," Bowman says.
After the flyby, Stern and his colleagues set out to look for a new goal in the Kuiper Belt, which extends from the edge of the Neptune's path to about 5 billion miles from the sun.
Until the 1990s, no one knew what was hiding there where sunlight is 0.05 percent as weak as it is on earth. Now the Kuiper belt is supposed to contain millions of icy objects, unused planetary building blocks left from the earliest days in the solar system.
These bodies are time capsules, preserved in deep freezing over the last 4.6 billion years. NASA says Ultima Thule is probably the most primitive planet object ever explored.
The Kuiper belt object was discovered with the Hubble Space Telescope in 2014. Subsequent observations suggest that it is small - no more than 20 miles across - and shaped like a peanut.
Astronomers believe that it is a contact binary, consisting of two objects that touch each other, or perhaps even a binary system, where two objects orbit each other.
The meeting with Ultima Thule will be short and technically demanding - even more so than the New Horizon flyby of Pluto. Pluto is about the size of the United States, Ultima could fit on Washington DC. This means that New Horizons has to come much closer to the space stone to investigate it, and the meeting will be much faster.
One day before the closest approach, Ultima Thule still takes only two pixels in images taken by New Horizons & # 39; camera screen. When new horizons run through space at 9 miles per second, it takes less than a day to put Ultima Thule back in a speck in the rear view mirror.
But New Horizon's performance so far suggests that it is ready for the challenge, Sade Stern. Measurements made on Saturday showed that the spacecraft was within 20 miles of the intended flight distance from the Ultima Thule and that the timing of the meeting will be within 2 seconds of what was expected.
"We call with something that is a mountain murder in black velvet in almost dark dark conditions, and we scream up to it [..] within 2 seconds of perfection," Stern said. "You can't get better than that."
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