While many celebrate the arrival of the new year with champagne, the team that operates New Horizons may have a special reason to open a bottle of bubbly: The spacecraft is set to stage the most distant encounter ever. On New Year’s Eve night, it’ll fly about 2200 miles from 2014 MU69, a small chunk of ice and rock more than four billion miles away.

New Horizons flew by Pluto in July of 2015. It had enough fuel left to maneuver to a second encounter in the Kuiper Belt, a “doughnut” of iceballs beyond the major planets. It was targeted for MU69, which was discovered by Hubble Space Telescope in 2014.

The encounter has taken a lot of preparation. Last year, for example, astronomers set up telescopes at a couple of remote locations to watch the object pass in front of a star. The observations revealed details about its size and shape. At the same time, telescopes in the air and in space looked for dangerous debris near MU69.

Because the object is only about 20 miles across, it’s no more than a dot in any Earth-based telescope. That makes it hard to know its exact location. So New Horizons itself has been tracking it since August. Its images have allowed navigators to plot a precise path for the craft, which will fly past MU69 at about 30,000 miles per hour.

It’ll take months for New Horizons to transmit all of its data to Earth — stretching out the celebrations of this distant encounter.

Script by Damond Benningfield