New Horizons

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.

The small object Ultima Thule swims amid a sea of distant stars in a new photo captured by NASA's approaching New Horizons around midnight EST (0500 GMT) on Dec. 1.

In less than 10 weeks, NASA's New Horizons spacecraft will explore the most distant target ever visited by a spacecraft. Mission team members don't know what to expect — and that's part of the fun.