Ultima Thule

Dream Destination in the Kuiper Belt

On December 31 of this year, the New Horizons spacecraft is set to fly by the distant object Ultima Thule. This tiny world lies in the Kuiper Belt, and the spacecraft has been en route to it since the July 2015 flyby of the Pluto system. The spacecraft has done another trajectory correction burn to home in on Ultima. Another one due about two weeks before closest approach. Then, on New Year’s Eve, the team and a bunch of its closest friends will be having the mother of all parties to celebrate the flyby, which takes place on 1 January 2019 at 05:33:00 UTC.

What is Ultima Thule?

Ultima Thule
rtist’s impression of NASA’s New Horizons spacecraft encountering 2014 MU69, a Kuiper Belt object that orbits one billion miles (1.6 billion kilometers) beyond Pluto, on Jan. 1, 2019. Credit: NASA/JHUAPL/SwRI/Steve Gribben

Until 2014, nobody knew Ultima Thule existed. But, the New Horizons team knew there had to be some distant worlds their spacecraft could visit after the Pluto flyby. So, they used the Hubble Space Telescope to search for possible worlds along the spacecraft’s trajectory. On June 26, 2014, the telescope spotted one. It was promptly dubbed 2014 MU69 and the team went to work on plotting a path to it. The object was renamed “Ultima Thule” based on a public voting process. It means “beyond the known world,” which is most appropriate for this little place out in the Kuiper Belt.

At the moment, nobody knows exactly all of Ultima’s characteristics. It lies about 6.5 billion kilometers from the Sun. That makes the New Horizons approach one of the most distant flybys ever made. Is it one world, or two? There’s a case to be made either way. If it’s two little worlds traveling together, that would make it a contact binary. If it’s one world, it may have a very odd two-headed potato shape. It’s pretty small, only about 30 km across. What the surface contains, its color and other characteristics will only be known as the spacecraft gets closer to take high-resolution images.

What will Ultima Thule Tell us about the Kuiper Belt?

The Kuiper Belt is the region of space where Ultima Thule orbits. It contains many small worlds, plus larger ones such as Pluto, Eris, and Makemake and a number of other dwarf planets. The appearance and composition of Ultima will tell scientists about cratering events (if it’s cratered). Special instruments will study its chemical makeup, and we’ll see if it has moons or a ring. Ultima Thule, by virtue of the fact that it lies so far out there, could well be made of some of the oldest materials in the solar system. They could tell scientists a LOT about what conditions were like in the early solar system.

Stay Tuned

As the days get closer to flyby, we should all be seeing more news about this mission. You can follow it at the mission website, which contains maps and clocks counting down to the event. It’s another great space exploration achievement from a a team that gave us the most amazing looks at Pluto using a spacecraft the size of a grand piano.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.