Ultima Thule is an unusual object found in the Kuiper Belt. It's located about 1 billion miles past dwarf-planet Pluto, which New Horizons visited in 2015. The pancake and nut comparison is a departure from earlier images that showed the two-lobed object looking more like a snowman.
NASA released a graphic showing how our understanding has changed thanks to additional data from New Horizons.
The rounded snowman images came within a day of New Horizons' closest approach on Jan. 1. Images taken 10 minutes after the approach highlighted a view of the object's crescent, giving scientists a better idea of its actual shape.
The blue dashes in the illustration show NASA's fudge factor. Ultime Thule may fill out those lines, or it may be closer to the flatter shape shown.