NASA just released the clearest image yet of Pluto's largest moon Charon taken by the New Horizons spacecraft. It's the best single-frame image of Charon the probe will get during this encounter period, with a resolution of 1.5 miles per pixel, and it says a lot about this space rock. "There’s so much interesting science in this one image alone," said New Horizons team member Cathy Olkin at today's press conference.

The image was taken with the LORRI instrument, the high-resolution imager on board the New Horizons probe, before the spacecraft made its closest approach to Pluto. The photo was taken on Monday July 13th at 10:41PM ET from about 290,000 miles away. "Charon just blew our socks off with the new image today," said Olkin.

"There’s so much interesting science in this one image alone."

Sitting at the northern pole of Charon is a dark area that the researchers have nicknamed "Mordor." The dark coloring may hint at a "thin veneer" over the surface, Olkin says.

The close shots reveal some new geography. On the top right edge of Charon in the image, there’s a deep canyon that’s about 4 to 6 miles deep. A series of troughs and cliffs extend about 600 miles across the planet from the northeast to the southwest. Just below that is a relatively smooth area with few craters, suggesting the ground there may be new.

"Perhaps it’s been geologically active or recently resurfacing that area," says Olkin. "So that’s very exciting to see as well."

Although it is considered a moon, Charon is so big compared to Pluto that the two space rocks actually orbit each other, like binary planets. A recent study published in Nature revealed that the gravitational influence of both Charon and Pluto drastically affects the orbits of Pluto's other moons — causing them to have very unpredictable paths. Better images of these moons will tell us more about their compositions, which have remained a mystery until now.