Stunning images of Pluto backlit thrill scientists, viewers
New panoramic images of Pluto backlit by the Sun, taken only 15 minutes after NASA’s New Horizons spacecraft’s closest approach on July 14, are thrilling scientists and viewers with stunning details of the dwarf planet’s diverse terrains, some of which are surprisingly Earth-like.
Released by the New Horizons team on Thursday, September 17, the images were taken by the spacecraft’s wide-angle Ralph/Multispectral Visual Imaging Camera (MVIC) as the spacecraft pivoted to photograph a 780-mile (1,250 km) wide region of the planet’s icy surface.
The photos, taken when New Horizons was 11,000 miles (18,000 km) from Pluto, show a dramatic close-up of its varied terrains, including icy mountains rising close to 11,000 feet (3,500 meters) high, flat plains, and rough terrain that appears to be cut by glaciers.
A panorama featuring the smooth, icy Sputnik Planum flanked by two mountain regions, one informally named Norgay Montes, and the other Hillary Montes, depicts a region 230 miles (380 kilometers) across.
Also visible in surprising detail is Pluto’s haze, which is composed of more than a dozen thin layers, reaching 60 miles above the surface.
One photo illustrates a small section of Pluto just 115 miles (185 kilometers) across where shadows of hills and mountains seen through fog look eerily Earth-like.
“This image really makes you feel you are there, at Pluto, surveying the landscape for yourself,” said principal investigator Alan Stern of the Southwest Research Institute in Boulder, Colorado.
“But this image is also a scientific bonanza, revealing new details about Pluto’s atmosphere, mountains, glaciers, and plains.”
Will Grundy of the Lowell Observatory, head of the New Horizons Composition team, noted the low-lying hazes suggest Pluto has constantly changing weather, much the way Earth does.
Soft, exotic ices, especially nitrogen ice, cover bright areas of Sputnik Planum, located in the heart-shaped region known as Tombaugh Regio. These ices may have evaporated from Sputnik Planum and subsequently fallen back to the surface east of the plain as snow.
Glaciers seen flowing back into Sputnik Planum in the panorama taken by Ralph appear remarkably similar to frozen streams near ice caps in Antarctica and Greenland.
Scientists were especially surprised to find evidence of a hydrological cycle on the planet similar to that on Earth. While Earth’s cycle involves water ice, Pluto’s is of soft and exotic ices, primarily nitrogen.
“Pluto is surprisingly Earth-like in this regard, and no one predicted it,” Stern emphasized.
Alan Howard of the University of Virginia, Charlottesville, a member of the mission’s Geology, Geophysics, and Imaging team, said no mission scientists expected to find a nitrogen-based hydrological cycle in the outer regions of the Solar System.
“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,” Howard said.
Laurel Kornfeld is an amateur astronomer and freelance writer from Highland Park, NJ, who enjoys writing about astronomy and planetary science. She studied journalism at Douglass College, Rutgers University, and earned a Graduate Certificate of Science from Swinburne University’s Astronomy Online program. Her writings have been published online in The Atlantic, Astronomy magazine’s guest blog section, the UK Space Conference, the 2009 IAU General Assembly newspaper, The Space Reporter, and newsletters of various astronomy clubs. She is a member of the Cranford, NJ-based Amateur Astronomers, Inc. Especially interested in the outer solar system, Laurel gave a brief presentation at the 2008 Great Planet Debate held at the Johns Hopkins University Applied Physics Lab in Laurel, MD.