A newly released view of the edge of Charon reveals a weird depression in the icy surface of Pluto's biggest moon — with an irregular peak that's plopped right in the middle.
The picture, captured on Tuesday during the New Horizons spacecraft's close encounter with Pluto and its moons, shows an area approximately 240 miles (390 kilometers) from top to bottom, including few visible craters.
"The most intriguing feature is a large mountain sitting in a moat," Jeff Moore, a scientist from NASA's Ames Research Center who leads New Horizons' geology, geophysics and imaging team, said Thursday in a NASA image advisory. "This is a feature that has geologists stunned and stumped."
Related: New Horizons Mission Reveals Huge Crater on Charon
The piano-sized New Horizons spacecraft was about 49,000 miles (79,000 kilometers) away from Charon when its Long Range Reconnaissance Imager took the picture. It's just a foretaste of the goodies that are expected to be released on Friday in conjunction with a 1 p.m. ET news briefing at NASA Headquarters.