Pluto is adorned with snow-covered mountains viewed by the New Horizons spacecraft which flew past the frozen world in 2015. This methane snow covers highlands at the equator of the distant former planet.
Cthulhu Regio, one of the most easily recognized of all the features on Pluto, runs halfway around the equator of the icy dwarf planet. At the eastern terminus of Cthulhu lies Sputnik Planum, a frozen plain. A mountain range stretches 260 miles across the southeastern region of the darkly hued feature, accompanied by craters and valleys.
Astronomers believe the dark color of Cthulhu is the result of methane being exposed to sunlight, forming a type of chemical known as tholins. This dark coating sharply contrasts with the frozen peaks seen in the newly released image from the far-flung spacecraft.
"That this material coats only the upper slopes of the peaks suggests methane ice may act like water in Earth's atmosphere, condensing as frost at high altitude," said John Stansberry, a member of the New Horizons science team at the Space Telescope Science Institute.
New Horizons mapped the presence of frozen methane on the surface of Pluto and found that the ice is located almost precisely where the spacecraft imaged snow-covered mountain peaks.
Cthulhu Regio is one of the darkest features on the surface of Pluto, shaped roughly like a whale. This extraterrestrial landmark sits to the west of Tombaugh Regio, the "heart" of Pluto. Nicknamed "The Whale," it was the first feature identified by astronomers viewing images from New Horizons. It received its informal name after online voters chose the demon from the mind of horror writer H.P. Lovecraft to be its namesake.
The resolution of the newly released image is approximately 2,230 feet per pixel, and features in the photograph cover 280 by 140 miles. The image was taken when the spacecraft was around 21,100 miles away from the frozen sphere.
New Horizons launched to Pluto in January 2006, before the most distant world was demoted to the class of dwarf planet. A previous image viewed from the spacecraft has showed Pluto's yellow-hued frozen canyons at its north pole. Prior to New Horizons' primary encounter with the frozen body, the vehicle was able to observe both Jupiter and asteroid 132524 APL. The spacecraft will continue to fly toward the outskirts of the solar system, and may yet encounter additional bodies orbiting far from the sun.
