While the world gets excited about the confirmation of gravitational waves, NASA’s New Horizons mission has been quietly and steadily releasing a stream of new information about the formerly neglected dwarf planet. The Pluto flyby revealed a surprisingly clear heart shape on its surface, and NASA has since been investigating the geological features that comprise the uneven pale spot.
One of the other surprises that New Horizons has revealed about Pluto is that it’s surprisingly geologically complex. This colour-coded image categorises each of its distinct geological areas in order to understand how Pluto’s surface has developed over time. The map focuses on the left side of Pluto’s heart, which is actually a nitrogen-ice plain that has been informally named Sputnik Planum.
As you can see in the key above, each different type of terrain has been categorised by both texture and morphology — meaning descriptors like “smooth, pitted, craggy, hummocky or ridged”. While not all of Pluto has been imaged at the same level of detail, the area covered by this map has all been imaged at a minimum resolution of 320 meters per pixel.
The black lines that traverse the ice plains represent troughs that mark the boundaries of cellular terrain in the nitrogen ice, while the red spot in the very bottom corner of the image represents the potential cryovolcanic feature that has been called Wright Mons. For the Lovecraft fans, the dark brown along the western edge of the map denotes an area of rugged highlands that has been informally named Cthulhu Regio. The bright yellow spots in this area are a number of large impact craters.
Even working from labs 7.5 billion kilometres away from the planet itself, scientists can take this data and figure out a basic chronology for the terrain’s formation. The simplest example of this kind of reasoning is the assumption that the yellow impact craters in Cthulhu must have been created after the rugged terrain of the area around it. It’s all part of mapping Pluto’s history, and gaining a greater understanding of one of the furthest bodies in our solar system.