Scientists have detected a large field of dunes on the surface of the distant, frigid dwarf planet Pluto apparently composed of windswept, sand-sized grains of frozen methane.
The dunes, spotted on images taken by Nasa’s New Horizons spacecraft during its 2015 flyby, sit at the boundary between a heart-shaped nitrogen glacier about the size of France called Sputnik Planitia and the Al Idrisi Montes mountain range made of frozen water, scientists said on Thursday.
Jani Radebaugh, a planetary scientist at Brigham Young University, said: “Pluto, even though it’s so far away from Earth and so very cold, has a riot of processes we never expected to see. It is far more interesting than any of us dreamed, and tells us that these very distant bodies are well worth visiting.”
The existence of the dunes, which cover about 775 sq miles (2,000 sq km), came as a surprise. There was some doubt about whether Pluto’s extremely thin atmosphere, mainly nitrogen with minor amounts of methane and carbon monoxide, could muster the wind needed to form such features.
Pluto, smaller than Earth’s moon with a diameter of about 1,400 miles (2,380 km), orbits about 3.6bn miles (5.8bn km) away from the sun, almost 40 times farther than Earth’s orbit, with a surface marked by plains, mountains, craters and valleys.
Methane, carbon monoxide, carbon dioxide and nitrogen, all gaseous on Earth, are rendered solid with Pluto’s temperatures near absolute zero. Pluto’s dunes were shaped by moderate winds reaching about 22 mph (35 kph) apparently blowing fine-grained frozen methane bits from mountaintops.
Pluto’s dunes resemble some on Earth like those in California’s Death Valley and China’s Taklamakan desert, though their composition differs, according to Radebaugh.
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SOURCE: The Guardian