sorry americans, the rest of the world does not do miles.

http://www.forbes.com/sites/bridaineparnell/2015/06/23/new-horizons-sees-mysterious-dark-patch-on-plutos-moon/

New Horizons Sees Mysterious Dark Patch On Pluto's Moon
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NASA’s New Horizons has spotted a dark, “anti-polar” cap on Pluto’s moon Charon, as the craft draws nearer to its rendezvous with the dwarf planet.

The far-flung probe is still three weeks away from its closest pass to Pluto and its five moons, but the mission team is making new discoveries every day from its reports.

Using its telescopic Long Range Reconnaissance Imager (LORRI), New Horizons has been able to spot light and dark terrain and what looks like a polar ice cap on Pluto, and now a dark anti-polar cap on Charon.

“This system is just amazing,” said Alan Stern, New Horizons Principal Investigator, from the Southwest Research Institute, in a statement. “The science team is just ecstatic with what we see on Pluto’s close approach hemisphere: Every terrain type we see on the planet – including both the brightest and darkest surface areas – are represented there, it’s a wonderland!

“And about Charon – wow – I don’t think anyone expected Charon to reveal a mystery like dark terrains at its pole,” he continued. “Who ordered that?”

etc etc.

some pretty good videos on nasa's website