Frozen Plains Discovered in Heart of Pluto
TEHRAN (Tasnim) - In the latest data from NASA's New Horizons spacecraft, a new close-up image of Pluto reveals a vast, craterless plain that appears to be no more than 100 million years old, and is possibly still being shaped by geologic processes.
The frozen region is north of Pluto's icy mountains, in the center-left of the heart feature, informally named "Tombaugh Regio" (Tombaugh Region) after Clyde Tombaugh, who discovered Pluto in 1930.
"This terrain is not easy to explain," said Jeff Moore, leader of the New Horizons Geology, Geophysics and Imaging Team (GGI) at NASA's Ames Research Center in Moffett Field, California. "The discovery of vast, craterless, very young plains on Pluto exceeds all pre-flyby expectations."
This fascinating icy plains region -- resembling frozen mud cracks on Earth -- has been informally named "Sputnik Planum" (Sputnik Plain) after the Earth's first artificial satellite. It has a broken surface of irregularly-shaped segments, roughly 12 miles (20 kilometers) across, bordered by what appear to be shallow troughs, ScienceDaily reported.
Scientists have two working theories as to how these segments were formed. The irregular shapes may be the result of the contraction of surface materials, similar to what happens when mud dries. Alternatively, they may be a product of convection, similar to wax rising in a lava lamp. On Pluto, convection would occur within a surface layer of frozen carbon monoxide, methane and nitrogen, driven by the scant warmth of Pluto's interior.
The Tuesday "heart of the heart" image was taken when New Horizons was 48,000 miles (77,000 kilometers) from Pluto, and shows features as small as one-half mile (1 kilometer) across. Mission scientists will learn more about these mysterious terrains from higher-resolution and stereo images that New Horizons will pull from its digital recorders and send back to Earth during the next year.
The New Horizons Atmospheres team observed Pluto's atmosphere as far as 1,000 miles (1,600 kilometers) above the surface, demonstrating that Pluto's nitrogen-rich atmosphere is quite extended. This is the first observation of Pluto's atmosphere at altitudes higher than 170 miles above the surface (270 kilometers).
