July 26, 2015

New Horizons Discovers Flowing Ices on Pluto

NASA’s New Horizons mission has found evidence of exotic ices flowing across Pluto’s surface, at the left edge of its bright heart-shaped area. New close-up images from the spacecraft’s Long-Range Reconnaissance Imager (LORRI) reveal signs of recent geologic activity, something scientists hoped to find but didn’t expect.

“We’ve only seen surfaces like this on active worlds like Earth and Mars,” said mission co-investigator John Spencer of SwRI. “I'm really smiling.”

The new close-up images show fascinating detail within the Texas-sized plain (informally named Sputnik Planum) that lies within the western half of Pluto’s heart-shaped region, known as Tombaugh Regio. There, a sheet of ice clearly appears to have flowed—and may still be flowing—in a manner similar to glaciers on Earth


New Horizons discovers flowing ices in Pluto’s heart-shaped feature. In the northern region of Pluto’s Sputnik Planum (Sputnik Plain), swirl-shaped patterns of light and dark suggest that a surface layer of exotic ices has flowed around obstacles and into depressions, much like glaciers on Earth.
Credits: NASA/JHUAPL/SwRI




In the northern region of Pluto’s Sputnik Planum, swirl-shaped patterns of light and dark suggest that a surface layer of exotic ices has flowed around obstacles and into depressions, much like glaciers on Earth.
Credits: NASA/JHUAPL/SwRI


Meanwhile, New Horizons scientists are using enhanced color images (see below) to detect differences in the composition and texture of Pluto’s surface. When close-up images are combined with color data from the Ralph instrument, they paint a new and surprising portrait of Pluto in which a global pattern of zones vary by latitude. The darkest terrains appear at the equator, mid-tones are the norm at mid-latitudes, and a brighter icy expanse dominates the north polar region. The New Horizons science team is interpreting this pattern to be the result of seasonal transport of ices from equator to pole.

This pattern is dramatically interrupted by the bright “beating heart” of Pluto


Four images from New Horizons’ Long Range Reconnaissance Imager (LORRI) were combined with color data from the Ralph instrument to create this enhanced color global view of Pluto. (The lower right edge of Pluto in this view currently lacks high-resolution color coverage.) The images, taken when the spacecraft was 280,000 miles (450,000 kilometers) away, show features as small as 1.4 miles (2.2 kilometers), twice the resolution of the single-image view taken on July 13.
Credits: NASA/JHUAPL/SwRI


Additionally, new compositional data from New Horizons’ Ralph instrument indicate that the center of Sputnik Planum is rich in nitrogen, carbon monoxide, and methane ices. “At Pluto’s temperatures of minus-390 degrees Fahrenheit, these ices can flow like a glacier,” said Bill McKinnon, of Washington University in St. Louis, deputy leader of the New Horizons Geology, Geophysics and Imaging team. In the southernmost region of the heart, adjacent to the dark equatorial region, it appears that ancient, heavily-cratered terrain (informally named “Cthulhu Regio”) has been invaded by much newer icy deposits.


This annotated image of the southern region of Sputnik Planum illustrates its complexity, including the polygonal shapes of Pluto’s icy plains, its two mountain ranges, and a region where it appears that ancient, heavily-cratered terrain has been invaded by much newer icy deposits. The large crater highlighted in the image is about 30 miles (50 kilometers) wide, approximately the size of the greater Washington, DC area.
Credits: NASA/JHUAPL/SwRI



The newly-discovered range of mountains rises one mile (1.6 kilometers) above the surrounding plains, similar to the height of the Appalachian Mountains in the United States. These peaks have been informally named Hillary Montes (Hillary Mountains) for Sir Edmund Hillary, who first summited Mount Everest with Tenzing Norgay in 1953.

“For many years, we referred to Pluto as the Everest of planetary exploration,” said New Horizons Principal Investigator Alan Stern of the Southwest Research Institute, Boulder, Colorado. “It’s fitting that the two climbers who first summited Earth’s highest mountain, Edmund Hillary and Tenzing Norgay, now have their names on this new Everest.”

View a simulated flyover using New Horizons’ close-approach images of Sputnik Planum and Pluto’s newly-discovered mountain range – Hillary Montes, in the video below.



SOURCES - NASA, Youtube

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