Dark Pluto Bares Its Heart : The Two-Way NASA's probe to Pluto has revealed stunning new pictures of the distant world. They show evidence of glaciers moving across the surface.
NPR logo Dark Pluto Bares Its Heart

Dark Pluto Bares Its Heart

"You can only get this image by going to Pluto and crossing to the far side and looking back," says scientist Alan Stern. NASA/JHUAPL/SwRI hide caption

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NASA/JHUAPL/SwRI

"You can only get this image by going to Pluto and crossing to the far side and looking back," says scientist Alan Stern.

NASA/JHUAPL/SwRI

Scientists with NASA's mission to Pluto revealed stunning new images of the dwarf planet on Friday. Researchers say the pictures suggest an icy world complete with glaciers and "snow" that falls through a wispy atmosphere.

The New Horizons spacecraft zipped past Pluto on July 14. It was traveling too fast to stop, but it snapped a trove of photos as it flew by. Because deep-space communication happens at sub-dial-up speeds, it will take months for all of the photos and data to come back.

Four images from New Horizons were combined to create this sharp global view of Pluto. The images were taken 280,000 miles from Pluto. NASA/JHUAPL/SwRI hide caption

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NASA/JHUAPL/SwRI

Four images from New Horizons were combined to create this sharp global view of Pluto. The images were taken 280,000 miles from Pluto.

NASA/JHUAPL/SwRI

But the 5 percent or so of data the spacecraft has returned has scientists gripped with excitement. "If you're seeing a cardiologist, you may want to leave the room," Alan Stern, the principal investigator of the New Horizons mission, said before unveiling the latest photos.

In the northern region of Pluto's Sputnik Planum, swirling ices appear to flow much like glaciers on Earth. NASA/JHUAPL/SwRI hide caption

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NASA/JHUAPL/SwRI

In the northern region of Pluto's Sputnik Planum, swirling ices appear to flow much like glaciers on Earth.

NASA/JHUAPL/SwRI

The images show Pluto is far from a dead lump of rock and ice. It appears that it experiences seasons during its 248-year orbit around the sun, according to Cathy Olkin, a scientist on the mission from the Southwest Research Institute in Boulder, Colo. In hotter times, the sun causes ice on the surface to evaporate and then settle in other regions.

Detailed images of the surface also show glaciers. A vast patch of the surface known as "Sputnik Planum" appears to be covered in what could be ice made of solid nitrogen. Even though it's a frosty -391 Fahrenheit, nitrogen ice is soft enough to flow, says Bill McKinnon, a geologist at Washington University in St. Louis, Mo. There is clear evidence that the nitrogen is flowing into craters and around mountains, which are believed to be made of solid water-ice.

A simulation of what it would be like to fly over Pluto's surface.

NASA/JHUAPL/SwRI YouTube

The source of the nitrogen ice is unknown. It could have been deposited when an icy body smashed into Pluto, or it could be upwelling from deep within the planet. "We're enjoying a great deal of animated discussion," McKinnon says.

Perhaps the most confounding image is one taken as New Horizons flew away from Pluto. It shows the planet back-lit by the sun, with its atmosphere clearly visible. Researchers say the atmosphere is much thinner than expected. One theory is that it may be "collapsing" as Pluto moves away from the sun and toward many years of cold, dark winter at the edge of the solar system.