NASA's New Horizons spacecraft is moving closer to Pluto, revealing stunning images of the mysterious dwarf planet.

The new images were taken at a distance of just under 50 million miles (20 million miles closer than images taken in mid-April) using the Long-Range Reconnaissance Imager (LORRI) on New Horizons, they contain about twice as many pixels as the previous images.

A sharpening technique called image deconvolution was used on the photographs. This technique allowed the researchers to see finer details of Pluto's surface such as a bright area that may be a polar ice cap.

"As New Horizons closes in on Pluto, it's transforming from a point of light to a planetary object of intense interest," said NASA's Director of Planetary Science Jim Green. "We're in for an exciting ride for the next seven weeks."

"These new images show us that Pluto's differing faces are each distinct; likely hinting at what may be very complex surface geology or variations in surface composition from place to place," added New Horizons Principal Investigator Alan Stern of the Southwest Research Institute in Boulder, Colo. "These images also continue to support the hypothesis that Pluto has a polar cap whose extent varies with longitude; we'll be able to make a definitive determination of the polar bright region's iciness when we get compositional spectroscopy of that region in July." 

The images will continue to improve as New Horizons moves closer in coming weeks, and the spacecraft will come into contact with Pluto on July 14.

"By late June the image resolution will be four times better than the images made May 8 [to] 12, and by the time of closest approach, we expect to obtain images with more than 5,000 times the current resolution," said Hal Weaver, the mission's project scientist at the Johns Hopkins University Applied Physics Laboratory (APL).