Scientists have solved one of Pluto's most puzzling mysteries

There are regions in Pluto where huge ice structures exist. Scientists finally think they know how they are formed.

Scientists have solved one of Pluto's most puzzling mysteries. In 2105, NASA's New Horizons spacecraft flew by Pluto. What it saw near Pluto's equator has baffled scientists ever since: Giant spires of methane ice that stand as tall as a NYC skyscraper.

"We asked ourselves why it forms all of those ridges as opposed to just being big blobs of ice on the ground."
-Jeffrey Moore, NASA Ames Research Center

The answer reveals that Pluto's climate is more dynamic than previously thought.

Smaller versions of these icy forests exist on Earth. The structures are called penitentes. They form near Earth's equator on top of tall mountains. Up there, conditions are right to turn snow straight to water vapor. This process — called sublimation — creates hard, sharp spikes of snow.

NASA scientists think the same process happens on Pluto. But this could only be possible if Pluto had been warmer in the past. Otherwise, the methane ice couldn't sublimate away. Scientists say this is proof of Pluto's complex climate.
The planet slightly cools, warms, and cools again over millions of years.

Turns out, Pluto isn't just a ball of ice after all.

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