Pluto’s White Capped Mountains
By: Danna Beltran
Picture captured by NASA’s New Horizons spacecraft of Pluto on July 14, 2015.
Our most detailed picture of Pluto to date was taken in July 2015 by the NASA New Horizons Spacecraft, as it flew by the dwarf planet. It was revealed in a new report published on October 13 that Pluto has white-peaked mountains much like Earth’s, making them the only known planets to have them. The resemblance between them is only superficial as these features, on Pluto, are actually made of methane frost.
The new report was published by the Nature Communications journal which established that Pluto’s mountains get their peaks whitened differently, when compared to Earth’s mountain tops. As confessed by Tanguy Bertrand, an astronomer at NASA's Ames Research Center in California, “Initially, it seemed logical that this high-altitude frost could form like on the Earth.” Snow on Earth is collected at the top of mountains due to the atmospheric temperatures decreasing with altitude where clouds and snow form at the top of the mountains, when water condenses. In Pluto, the atmosphere is heated by the Sun and actually gets warmer as altitudes increase, with surface temperatures remaining consistently cold. It was discovered that there is no need for wind to bring gaseous methane up the mountains, as it is already up there. This implies that these tall mountains stick up into a region rich in methane where on the cold surfaces methane forms frost giving it its features.
New photographs of the New Horizons spacecraft illustrate that, as seasons change, the frost deposits do as well. As shown in the photographs, some areas of the mountains look reddish rather than brown. This leads to the scientific belief that methane frost was there in another season, offering protection from things like cosmic rays that can darken the surface. Tanguy Bertrand adds that, “This discovery teaches us that there are still plenty of physical and dynamical processes out there in space that we do not know about, and that climates can be very different than that of Earth (despite forming a similar landscape).” Using Pluto and other planetary bodies as natural laboratories to explore, highlights the importance of studying them, as these investigations can lead to a new perspective on Earth’s climate. Understanding Pluto’s climate not only helps researchers understand what is unique and common from it when compared to Earth's, but it also helps place Pluto on the scale of other climates known in our solar system.