Washington, Feb 23 (IANS): NASA's New Horizons spacecraft has sent back the sharpest possible pictures of the Kuiper Belt Object (KBO), nicknamed Ultima Thule, captured just before its closest approach.

The 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 (officially named 2014 MU69) at 12.33 a.m. EST on January 1, 2019.

The latest images offer a resolution of about 110 feet (33 metres) per pixel - the highest spatial resolution of any New Horizons has taken or may ever take - during its entire mission, Project Scientist Hal Weaver, of the Johns Hopkins Applied Physics Laboratory, said in a statement.

Swooping within just 3,500 km, New Horizons flew approximately three times closer to Ultima than it zipped past its primary mission target, Pluto, in July 2015.

"Bullseye!" said New Horizons Principal Investigator Alan Stern, of the Southwest Research Institute (SwRI).

"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," he added.

The higher resolution brings out many surface features - bright, enigmatic, roughly circular patches of terrain - that were not apparent in earlier images.

In addition, many small, dark pits near the terminator (the boundary between the sunlit and dark sides of the body) are better resolved.

Ultima is a smaller object than Pluto, but the Ultima flyby was done with the highest navigation precision ever achieved by any spacecraft before.

New Horizons is nearly 6.64 billion km from Earth. At that distance, radio signals, travelling at light speed, reach the large antennas of NASA's Deep Space Network six hours and nine minutes after New Horizons sends them.