NASA's New Horizons Ready for Historic Flyby of Ultima Thule in the Kuiper Belt

NASA's New Horizons spacecraft will ring in the new year with an epic flyby at the edge of the solar system, and the stage is set for a truly historic encounter. And it's happening amid a partial government shutdown.

"Very few teams have had this experience and this privilege of crossing the entirety of our solar system on a mission," Stern said in the webcast. "Really only the Pioneers and the Voyagers that came before us." 

Not a lot is known about Ultima Thule. It is much smaller than Pluto, but its exact size and shape are unknown. It may have a reddish tint, but it isn't reflecting light like scientists initially expected, raising eyebrows ahead of Tuesday's flyby.