‘Surprising’ methane dunes found on Pluto

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The dwarf planet Pluto (R) and its largest moon Charon are shown July 11, 2015 as NASA's New Horizons spacecraft was nearing its flyby.

But perhaps the most surprising outcome of New Horizons' journey was not the deeper peek into Pluto's oddities. In the western lobe of that heart, a plain called Sputnik Planitia, Telfer and other planetary scientists spotted something peculiar.

NASA's New Horizons spacecraft looked back toward the sun and captured this near-sunset view of the rugged, icy mountains and flat ice plains extending to Pluto's horizon.

After scientists observed dunes on Pluto that were lurking close to mountains and the Sputnik Planitia ice plain, they conducted numerical and spectral modeling, as well as spatial analysis on the area.

The author of the study, Matt Telfer at the Plymouth University of the United Kingdom, said in a statement, "The best imagery prior to New Horizons was 12 pixels across for the whole dwarf planet". But nitrogen ice is too soft to form dunes, which requires the particles to roll and jump to form the rippled patterns.

"And we can measure some basic things like how far apart they are spaced, and have an estimate at least of the wind speeds that are forming them". To hold a handful of methane grains, if you could handle the cold, would be like scooping up "really fine sand", Radebaugh said.

To be able to form, dunes need an atmosphere dense enough to make wind transport possible, a supply of dry particles, and a mechanism that lifts particles off the ground.

Scientists are seeing the surface of Pluto for the first time. It also found that they were created by moderate winds of around 19 to 25 miles per hour (30 to 40 kilometers per hour). An worldwide research team on Thursday conveyed the fact that the Pluto is covered with surprising dunes of methane ice.

As for the process of "lofting" the grains off the ground, the paper suggested that the driver could be a slight warming from the distant Sun, raising the temperature above the frost point of nitrogen: -230C. The winds may be powered by the sublimation of surface ice which turns from solid directly into gas when sunlight hits.

Scientists were surprised to find dunes given Pluto's thin, weak atmosphere.

"He quoted the late Sir Patrick Moore, the famous BBC Sky at Night presenter, describing Pluto in 1955 as "...plunged in everlasting dusk, silent, barren, and touched with the chill of death..." and says that that perspective has to shift.

It is now heading towards an even more distant world in our solar system's so-called Kuiper Belt, or Twilight Zone. Sastrugi - parallel wave-like ridges caused by winds on a hard snow surface; barchan - crescent mounds that tend to be wider than they are long; and seif - linear dunes with two slip faces, are just three of the very different types of dune that are found on Earth. Not only Earth, dunes can also be seen in Venus, Mars and even in Saturn's natural satellite Titan. These dunes may have similar shapes, but are produced by slightly different processes, depending on the environmental conditions of the body in question.

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