Azerbaijan National Academy of Science

Mountains on Pluto have snowcaps that may have formed from the top down as opposed to the bottom up, the reverse of how snow caps form on Earth, a new study finds.

When NASA's New Horizons spacecraft flew by Pluto in 2015, it revealed a surprisingly complex and diverse landscape on the faraway world. Pluto's frozen surface varies greatly, featuring regions dominated by different kinds of ices — from frozen methane to frozen nitrogen and even water ice.

"The bedrock of Pluto is made of water ice, but it is so cold that the ice is harder than rock," study lead author Tanguy Bertrand, a planetary scientist at NASA Ames Research Center in Moffett Field, California, told Space.com. "The mountains on Pluto are made up of this cold hard water ice."

space.com