Last week NASA released glorious views of Pluto at sunset, highlighting the many haze layers in the atmosphere. We saw the icy mountains surrounding Tombaugh Regio and Sputnik Planum in great detail. As breathtaking as those images were, the latest views of the icy dwarf planet are even more incredible. Today we see the highest resolution color images downlinked so far. The images were captured as the spacecraft flew through the system on July 14 and were downlinked on September 19.
The newest high-resolution images of Pluto both dazzle and mystify, highlighting never-before-seen topographic and compositional details. Captured by New Horizons’ Ralph/Multispectral Visual Imaging Camera (MVIC), this enhanced-color view showcases Pluto’s varied terrain painted in subtle colors from pale blue to yellow to deep red. Many of the landforms have their own colors, revealing clues to Pluto’s complex geological and climatological story.
“It’s a unique and perplexing landscape stretching over hundreds of miles,” said William McKinnon in a statement. McKinnon is New Horizons Geology, Geophysics and Imaging (GGI) team deputy lead from Washington University in St. Louis. “It looks more like tree bark or dragon scales than geology. This’ll really take time to figure out; maybe it’s some combination of internal tectonic forces and ice sublimation [turning straight from solid to gas] driven by Pluto’s faint sunlight.”
An extended color image of Pluto. The textured mountains, informally named the Tartarus Dorsa, are patterned in a puzzling way. Credits: NASA/JHUAPL/SWRI
Tree bark, dragon scales or even snakeskin are not words one usually uses to describe another world, but that’s exactly what this extended color view of Pluto looks like. We see a bizarrely textured mountain range – informally named the Tartarus Dorsa – towering along Pluto’s terminator line (the boundary between day and night). This view shows us an area roughly 530 kilometers (330 miles) across – roughly the distance from Los Angeles to San Jose, CA – taken by Ralph/MVIC featuring details as small as 1.3 kilometers (0.8 miles) wide. Tartarus Dorsa features red material (perhaps tholins?) in between intriguing patterns of blue-gray ridges.
“We used MVIC’s infrared channel to extend our spectral view of Pluto,” said John Spencer, a GGI deputy lead from Southwest Research Institute (SwRI) in Boulder, Colorado. “Pluto’s surface colors were enhanced in this view to reveal subtle details in a rainbow of pale blues, yellows, oranges, and deep reds. Many landforms have their own distinct colors, telling a wonderfully complex geological and climatological story that we have only just begun to decode.”
This cylindrical projection map of Pluto is the most detailed color map of Pluto so far. Image credits: NASA/JHUAPL/SWRI
Also released is the most detailed color map of Pluto (above) thus far. To create the cylindrical projection map, recent color imagery from Ralph/MVIC was draped over a base map of LORRI images. All images, including the map, can be zoomed in to reveal even more details. Maps like this one are vital to our understanding of Pluto’s complex history.
“It's like the classic chicken-or-egg problem,” said Will Grundy, New Horizons surface composition team lead from Lowell Observatory in Flagstaff, Arizona. “We’re unsure why this is so, but the cool thing is that New Horizons has the ability to make exquisite compositional maps across the surface of Pluto, and that’ll be crucial to resolving how enigmatic Pluto works.”
High-resolution image reveals craters, faulted mountain blocks, and the vast basin informally called Sputnik Planum. Credits: NASA/JHUAPL/SWRI
So far, views of the vast basin dubbed Sputnik Planum that we’ve seen show a bright, smooth surface. New images reveal that Sputnik Planum is actually littered with dense patterns of pits, low ridges, and scalloped terrain. Last week we saw evidence of dune and even an Earth-like hydrological process occurring in the Planum; these processes could be what is shaping the terrain.
The textured surface surrounds two isolated ice mountains. Credits: NASA/JHUAPL/SWRI
New Horizons also supplied us with some fascinatingly complex compositional data. The probe’s Ralph/LEISA infrared spectrometers mapped Pluto’s global composition, revealing striking contrasts in methane ice. Sputnik Planum has an abundance of methane, while Cthulhu Regio and the mountains along Sputnik Planum’s west flank have none. Globally, higher concentrations of methane are found on bright plains and along crater rims, while darker regions have none. Scientists are still trying to determine why there’s such a contrast.
“With these just-downlinked images and maps, we’ve turned a new page in the study of Pluto beginning to reveal the planet at high resolution in both color and composition,” added New Horizons Principal Investigator Alan Stern, of SwRI. “I wish Pluto’s discoverer Clyde Tombaugh had lived to see this day.”
Left: A map of methane ice abundance, with stronger methane absorption shown in purple. Right: The methane map is combined with higher-resolution images from the spacecraft’s Long Range Reconnaissance Imager (LORRI). Credits: NASA/JHUAPL/SWRI