New Horizons

As 2018 draws to a close, one group of people plans to celebrate something far more unusual — a flyby of Ultima Thule, the most distant solar system object ever explored. Here's what to expect.

As NASA's New Horizons probe nears its second target, we investigate what's lurking at the edge of the solar system.

NASA's New Horizons spacecraft is about the make the most distant planetary flyby in the history of spaceflight, and you can follow the action live.

New Horizons principal investigator Alan Stern discusses the mission and its Jan. 1 flyby of the mysterious, distant object Ultima Thule.

There's something weird going on with Ultima Thule, the distant object that NASA's New Horizons spacecraft will fly by just 10 days from now.

NASA's history-making New Horizons spacecraft may not be done with deep-space flybys after its highly anticipated New Year's Day encounter.

The free Pluto Safari app let New Horizons fans track the probe's flyby of Pluto in 2015, and now it's set to follow the journey past the distant body Ultima Thule on New Year's Day.

NASA's New Horizons spacecraft will indeed get very close to the mysterious, distant object Ultima Thule on New Year's Day.

NASA's New Horizons probe is getting set for the farthest-out flyby in history, and you can send some words of encouragement to help the spacecraft get across the finish line.