Dramatic Pluto images reveal foggy weather, frosty glaciers

A new backlit viewof Pluto sent home by the New Horizons spacecraft reveals closeups of an Arctic-like landscape against a dramatic, layered sky.

"This image really makes you feel you are there, at Pluto, surveying the landscape for yourself," said Alan Stern, principal investigator of the New Horizons mission, in a statement accompanying the release of the new images Thursday.

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The image was captured by New Horizons as it looked back at Pluto 15 minutes after making its closest approach to the dwarf planeton July 14.

Stern called the imagea "scientific bonanza."

Among the new details visible in the images are:

• More than a dozen haze layers in Pluto's thin nitrogen atmosphere between the ground and an altitude of 100 kilometres.
• Low-lying hazes in some areas that suggest the weather changes daily on Pluto as it does on Earth.
• Evidence of a glacial cycle similar to the one on Earth that builds up glaciers and then sees them flowing into the sea.

The main differences between natural cycles involving glaciers on Earth and on Pluto isthat the glaciers on Pluto are made of frozen nitrogen, not water, and scientists aren't sure whether a liquid is involved,saidAlan Howard, a University of Virginia planetary scientist who is on theNew Horizons geology, geophysics and imaging team, in anemailto CBC News.

Ice appears to be evaporating from one area of an icy plain known as "SputnikPlanum." After travelling tens tohundreds of kilometres through the atmosphere,It's re-depositedto the east, "probably as frost."

He added in a statement, "We did not expect to find hints of a nitrogen-based glacial cycle on Pluto operating in the frigid conditions of the outer solar system."

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As on Earth, this cycle is thought to be driven by the sun, even though the sun is far dimmer on Pluto which is on average 40 times farther away from the sun than Earth.