New Horizons scientists have discovered an expanse of terrain they describe as “fretted” on Pluto, something they haven't seen it anywhere else on the planet.
Scientists spotted this rare terrain as they peeked through the images of Pluto’s informally named Venera Terra region.
The terrain, which is shown in the enhanced-color image at top, consists of bright plains divided into polygon-shaped blocks by a network of dark, connected valleys typically reaching a few miles (3 to 4 kilometers) wide. Numerous impact craters of up to 15 miles (25 kilometers) in diameter also dot the area, implying the surface formed early in Pluto’s history.
— NASA (@NASA) May 20, 2016
Compositional data from New Horizons’ Ralph/Multispectral Visible Imaging Camera (MVIC), shown in the bottom image, indicate that the blocks are rich in methane ice - methane is susceptible to sublimation at Pluto surface conditions.
The images were obtained at a range of approximately 21,100 miles (33,900 kilometers) from Pluto, about 45 minutes before New Horizons’ closest approach on July 14, 2015. The resolution of these MVIC images is approximately 2,230 feet (680 meters) per pixel.
According to NASA, in fact, it’s rare terrain across the solar system - the only other well-known example of such being Noctis Labyrinthus on Mars.