NASA's New Horizons returns sharpest views of Ultima Thule

NASA's New Horizons spacecraft has sent back the sharpest possible pictures of the Kuiper Belt object nicknamed Ultima Thule, the most distant object ever explored.

This Jan. 1, 2019 photo made available by NASA on Friday, Feb. 22, 2019 shows the Kuiper belt object Ultima Thule photographed by the New Horizons spacecraft, minutes before its closest approach. [Photo: AP/NASA/Johns Hopkins Applied Physics Laboratory/Southwest Research Institute, National Optical Astronomy Observatory]

These new images of Ultima Thule was obtained by the telephoto Long-Range Reconnaissance Imager (LORRI) just six-and-a-half minutes before New Horizons' closest approach to the object at 12:33 a.m. EST on Jan. 1, according to a release of the mission team on Friday.

The images offer a resolution of about 110 feet (33.5 meters) per pixel.

Their combination of high spatial resolution and a favorable viewing angle gives the team an unprecedented opportunity to investigate the surface, as well as the origin and evolution of Ultima Thule.

"Getting these images required us to know precisely where both tiny Ultima and New Horizons were - moment by moment - as they passed one another at over 32,000 miles per hour in the dim light of the Kuiper Belt, a billion miles beyond Pluto," said New Horizons Principal Investigator Alan Stern.

"This was a much tougher observation than anything we had attempted in our 2015 Pluto flyby," he added.

The higher resolution brings out many surface features of Ultima Thule, including several bright, enigmatic, roughly circular patches of terrain, and many small, dark pits near the terminator, the boundary between the sunlit and dark sides of the body.

"Whether these features are craters produced by impactors, sublimation pits, collapse pits, or something entirely different, is being debated in our science team," said deputy project scientist John Spencer.

The latest images have the highest spatial resolution any New Horizons has taken, or may ever take, during its entire mission, according to the team.

The New Horizons mission, launched in January 2006, aims to understand worlds at the edge of the solar system by making the first reconnaissance of the dwarf planet Pluto, and by venturing deeper into the distant, mysterious Kuiper Belt -- a relic of solar system formation.