Enigmatic ridges on Pluto may be the remains of vanished nitrogen glaciers

Image of Pluto's surface.

Enlarge / Washboard terrain
fills the basins in the right of this image. (credit: NASA/JHUAPL/SwRI)

As we’ve gathered more details about the other planets of the
Solar System, we’ve largely managed to explain the geography we’ve
found by drawing analogies to things we’re familiar with from
Earth.
Glaciers and wind-driven erosion
produce similar results both
here and on Mars, for instance. But further out in the Solar
System, the materials involved in the geology change—water ice
becomes as hard as rock, and
methane and nitrogen freeze
—which raises the prospect of some
entirely unfamiliar processes.

This week, scientists proposed that some weird terrain found on
Pluto could be the product of large fields of nitrogen ice
sublimating off into the atmosphere. While this explanation could
account for some properties of Pluto’s geography, it doesn’t
explain why the process resulted in a series of parallel
ridges.

On the washboard

The strange terrain lies to the northwest of Sputnik Planitia,
the heart-shaped plane that dominates the side of Pluto we have the
best images of. Called “washboard” or “fluted,” the area consists
of large numbers of roughly parallel ridges with roughly a
kilometer or two separating them. Aside from their appearance and
general orientation, these ridges don’t seem to have a lot in
common. They’re discontiguous and don’t fill the entire region.
They run down slopes and spread across valley floors—in some
cases a single ridge will run down a slope and then flatten out.
And in several cases, they create a starburst-like pattern on along
the walls of craters.

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Source: FS – All – Science – News
Enigmatic ridges on Pluto may be the remains of vanished nitrogen glaciers