Sunset on Pluto: Breathtaking NASA Photo Shows Mountains, Wispy Atmosphere

A spectacular new image from NASA's New Horizons spacecraft shows Pluto in an entirely new light.

The photo, which New Horizons took during its epic July 14 flyby of Pluto, captures a gorgeous sunset view. Towering ice mountains cast long shadows, and more than a dozen layers of the dwarf planet's wispy atmosphere are clearly visible.

"This image really makes you feel you are there, at Pluto, surveying the landscape for yourself," New Horizons principal investigator Alan Stern, of the Southwest Research Institute in Boulder, Colorado, said in a statement today (Sept. 17). "But this image is also a scientific bonanza, revealing new details about Pluto's atmosphere, mountains, glaciers and plains." [See more Pluto photos by New Horizons]

NASA’s New Horizons spacecraft looked back toward the sun 15 minutes after its closest approach to Pluto on July 14, 2015, capturing this near-sunset view of the dwarf planet’s icy mountains and flat ice plains. The image was taken from a distance of 11,000 miles (18,000 kilometers) from Pluto; the scene is 780 miles (1,250 km) wide. (Image credit: NASA/JHUAPL/SwRI)

New Horizons captured the panorama, which covers a stretch of land 780 miles (1,250 kilometers) across, using the probe's wide-angle Ralph/Multispectral Visual Imaging Camera on July 14, just 15 minutes after closest approach to Pluto.

The spacecraft turned back and looked toward the sun, snapping the photo at a distance of just 11,000 miles (18,000 km) from the dwarf planet, NASA officials said. (At closest approach, New Horizons was about 7,800 miles, or 12,550 km, from Pluto's surface.)

The result was a new perspective on Pluto's Norgay Montes and Hillary Montes, two ranges of ice mountains that rise up to 11,000 feet (3,500 meters) above the dwarf planet's frigid surface. The backlit photo also reveals new details about Pluto's nitrogen-dominated atmosphere, showing many different layers, extending from ground-bound fog to wispy tendrils more than 60 miles (100 km) up.

The setting sun illuminates fog or near-surface haze on Pluto in this small section of an image taken by NASA’s New Horizons probe on July 14, 2015, when it was 11,000 miles (18,000 kilometers) from the dwarf planet. The image covers a stretch of land 115 miles (185 km) wide. (Image credit: NASA/JHUAPL/SwRI)

"In addition to being visually stunning, these low-lying hazes hint at the weather changing from day to day on Pluto, just like it does here on Earth," Will Grundy, leader of New Horizons' composition team from Lowell Observatory in Flagstaff, Arizona, said in the same statement.

The new panorama and other recently downloaded New Horizons images also shed light on how ice — likely made of nitrogen and other materials rather than water — flows into a vast, flat glacial plain known as Sputnik Planum. Some of Sputnik Planum's ice apparently evaporates, gets deposited in a region of rough terrain to the east and then flows back down into the plain as glaciers, via a system of valleys.

These glaciers are similar to those seen in Greenland and Antarctica here on Earth, researchers said.

This New Horizons image shows how ice (probably frozen nitrogen) is flowing from Pluto’s mountains through valleys (outlined by red arrows) onto the plains known as Sputnik Planum; the "flow front" there is outlined by blue arrows in this photo, which covers an area 390 miles (630-kilometer) wide. (Image credit: NASA/JHUAPL/SwRI)

"We did not expect to find hints of a nitrogen-based glacial cycle on Pluto operating in the frigid conditions of the outer solar system," said Alan Howard of the University of Virginia, a member of the mission's geology, geophysics and imaging team. "Driven by dim sunlight, this would be directly comparable to the hydrological cycle that feeds ice caps on Earth, where water is evaporated from the oceans, falls as snow and returns to the seas through glacial flow."

"Pluto is surprisingly Earth-like in this regard, and no one predicted it," Stern added.

New Horizons beamed the new backlit panorama home to mission control on Sunday (Sept. 13), and NASA released the photo today.

The world can expect to see many more stunning new views from the Pluto flyby over the coming year or so. New Horizons relayed just 5 percent of its flyby data back in the immediate aftermath of the close encounter, keeping the vast majority on board for later transmission. That data dump began in earnest earlier this month and is expected to take about 12 months, New Horizons team members have said.

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Mike Wall Senior Writer
Michael was a science writer for the Idaho National Laboratory and has been an intern at, The Salinas Californian newspaper, and the SLAC National Accelerator Laboratory. He has also worked as a herpetologist and wildlife biologist. He has a Ph.D. in evolutionary biology from the University of Sydney, Australia, a bachelor's degree from the University of Arizona, and a graduate certificate in science writing from the University of California, Santa Cruz.