A newly discovered, strange-looking feature on Pluto's big moon Charon could be a "mountain sitting in a moat," according to NASA.
Scientists working with the New Horizons spacecraft found the odd surface feature in an image taken just before the probe made its close flyby of Pluto on July 14. The apparent mountain in a moat is located on the right side of the moon, and scientists don't have a good explanation for its exact appearance quite yet.
“The most intriguing feature is a large mountain sitting in a moat,” Jeff Moore New Horizons’ Geology, Geophysics and Imaging team leader said of the image in a statement.
“This is a feature that has geologists stunned and stumped.”
New Horizons scientists hoping to learn more about the formation likely won't have to wait too long. This image -- taken about 1.5 hours before the flyby from a range of 49,000 miles away -- is only a compressed preview of higher resolution photos to come.
While New Horizons has already flown by Pluto, it collected more than 1,200 photos of the dwarf planet and its five moons, and the spacecraft still needs to send the vast majority of those pictures down to the ground in the next year or more.
Researchers and the public got their first detailed look at Charon yesterday. That image revealed a 4- to 6-mile-deep canyon that looks like a notch taken out of the right limb of the moon.
Wednesday's photo also gave scientists a good view of the moon's dark polar region -- unofficially named Mordor, after the land of shadow in Tolkein's Lord of the Rings . The coloration in that area of Charon might actually be due to Pluto's atmosphere sloughing off the dwarf planet and gravitating to Charon's north pole, but scientists won't be sure if that hypothesis is correct until more data comes through.
For now, scientists will just have to work with what New Horizons has already revealed about Charon.
“It’s a small world with deep canyons, troughs, cliffs and dark regions that are still mysterious to us," New Horizons deputy project scientist Cathy Olkin said during a news conference revealing a Charon photo Wednesday.
