One billion miles beyond Pluto, in the most remote areas of the solar system, is an object called Ultima Thule. His name means "Beyond the known world".
Although scientists have discovered it with telescopes, they do not know much about it. What they have learned from their observations is that Ultima Thule is a stone in the Kuiper Belt of the Solar System, the area outside of Neptune. It is irregular in shape and has a diameter of about 18 miles. It might look as if two potatoes had been cooked together:
On January 1, the New Horizons spacecraft, famous for flying from Pluto, will pass Ultima Thule to explore this strange rock and learn more about the evolution of our solar system ,
After flying past Pluto in 2015, mission scientists chose Ultima Thule as the next stop in the Kuiper Belt, mainly because New Horizons had the ability to reach it with its remaining fuel, because Ultima is the farthest object in the solar system that humanity has ever explored, and one of the most primitive.
Because Ultima is in such a cold, remote and tranquil region of the Solar System, it has probably left the Sun undisturbed for almost the entire Solar System age.
"We expect Ultima to be the best-preserved sample of a planetary building block ever studied," writes Alan Stern, chief investigator for New Horizons, in a blog post. "What will Ultima reveal? Nobody knows. For me, that's the most exciting – that's pure exploration and basic research! "
To star, the flyby – and the images that emerge from it – are taken with the famous photo of the" Earthrise " Similar to a photo taken 50 years ago by the Apollo 8 mission, this photo was taken when humans first circled the moon, marking the first time we saw our own planet from the perspective of another world.  This view of the rising Earth greeted the Apollo 8 astronauts as they entered the lunar orbit behind the Moon. SSPL on Getty Images
NASA has made history by continuing to explore it "As a result, we made Carl Sagan's prediction that the planets would be transformed from light points into real and explored worlds in just one or two generations."
For hay te Ultima Thule is just a blip. This is what the New Horizons camera looks like as the spacecraft approaches closer and closer.
But soon it will be much more than a blip. The images of the object may be weaker than those of Pluto (it is a billion miles from the Sun). New Horizons, however, has a camera that can make impressive details. Just look at the pictures of Pluto.
Let us remember that Pluto was only a point of light. New Horizons has proven to be an incredible, dynamic world with a beautiful heart-shaped ice surface. This GIF shows the best image of Pluto that we turned from 2015 into what New Horizons saw on its historic flyby. It became a beautiful thing from a dirty spot.
(And yes, scientists are still debating whether Pluto deserves to be a planet instead of a dwarf planet.)
New Horizons will arrive at Ultima Thule at 12:00 pm. On January 1, at 11:00 pm, just after the New Year. You can follow NASA's live TV stream with NASA (see below). New Horizons will also bring messages from the public (submissions ended December 21) to celebrate the distant arrival.