NASA’s deep solar system probe “New Horizons” made history in 2015 being the first space probe to visit Pluto, providing stunning images of the planet beloved by kids all over the world. After its mission completion on sending over the enormous volumes of data it collected, the probe’s mission was extended to do what no probe had done before. It was repurposed to now visit the Kuiper belt.
What is the Kuiper Belt?
For those of you who do not know what the Kuiper belt is, it is just a big cloud of protoplanetary material or giant space rocks that orbit the sun outside the orbit of Neptune. This bunch of space rocks are essentially the remanants of failed planets. The same stuff the solar system planets are made out of. It is thought that these rocks ( actually solidified ice, methane etc ) failed to become planets because they were too sparsely spaced to form stable planets. Pluto itself is thought to be a Kuiper Belt Object or KBO
In 2016, using the Hubble Space Telescope, a few KBOs were identified that NASA engineers and scientists thought could be suitable for New Horizons to visit and return data, given the amount of fuel left on the craft and the life of its radioisotope generators. Finally a space rock dubbed “Ultima Thule” was identified
New Horizons Reaches asteroid 486958 (2014 MU69) “Ultima Thule”
On Jan 1 2019, New Horizons made its closest flyby to Ultima Thule making it history as its the furthest object any spacecraft has visited. New Horizons came withing 2200 Km of the KBO. Reaching this Kuiper Belt object is truly and outstanding feat of mankind.

As you can see, the asteroid has a snowman like structure. Scientists think the two parts of the ball were distinct objects before, until they collided and coalesced togther. the asteroid is approx 20 miles by 10 miles