CAPE CANAVERAL, Fla. (AP) - Scientists have discovered dunes on Pluto made of tiny frozen grains of methane.
The pale gray and white ridges were revealed by NASA's New Horizons spacecraft during its 2015 flyby. A British-led team announced the findings Thursday in the journal Science.
Researchers said the dunes appear to be made mostly of icy specks of methane the size of sand. Thought to be relatively recent, the dunes are located in Pluto's heart-shaped region at the base of mountains with methane snowcaps.
Scientists were surprised to find dunes given Pluto's thin, weak atmosphere. They suggest surface nitrogen ice transformed into gas that lifted methane particles. Pluto's gentle winds then carried and deposited the grains.
Dunes already have been found on Mars, Venus, Saturn's moon, Titan, and even a comet.