NASA’s New Horizons spacecraft is completely changing what we know about Pluto and its moons. No one knew what to expect when New Horizons soared past Pluto in July. But the images released so far have blown everyone away. From the astronomy fans like us to the scientists at NASA.
The most recent image dump focuses on Pluto’s largest moon, Charon. Most of the New Horizons team figured Charon would be a drab moon painted by craters. Instead, they find a moon covered in mountains, canyons, landslides and surface-color variations.
“We thought the probability of seeing such interesting features on this satellite of a world at the far edge of our solar system was low,” said Ross Beyer, an affiliate of the New Horizons Geology, Geophysics and Imaging (GGI) team. “But I couldn’t be more delighted with what we see.”
You can clearly see the surface-color variations in the high-resolution enhanced color image of Charon below.
Your eyes are immediately drawn to the large reddish area at the moon’s north pole. The area is informally named Mordor Macula. Yep, that Mordor.
High-resolution images taken by the Long Range Reconnaissance Imager reveal canyons and rolling plains across Charon’s surface.
You can see vast canyons just north of the moon’s equator. How big are we talking? Charon’s canyon system stretches more than 1,000 miles across the entire face of Charon, and could stretch around Charon’s far side. This canyon system is four times as long as the Grand Canyon and twice as deep in certain areas.
It’s these canyons that point to enormous geological activity in Charon’s past.
“It looks like the entire crust of Charon has been split open,” said John Spencer, deputy lead for GGI at the Southwest Research Institute in Boulder, Colorado. “With respect to its size relative to Charon, this feature is much like the vast Valles Marineris canyon system on Mars.”
It’s not just the canyons that hint at geological activity, either. The plains south of Charon’s canyon system have fewer large craters than the regions to the north. Fewer craters mean the surface in this area is likely younger. Plus, the smoothness of the plains points to wide-scale resurfacing.
One possibility the New Horizons team is considering is cryovolcanism. “The team is discussing the possibility that an internal water ocean could have frozen long ago, and the resulting volume change could have led to Charon cracking open, allowing water-based lavas to reach the surface at that time,” said Paul Schenk, a New Horizons team member from the Lunar and Planetary Institute in Houston.
With every new image comes new understanding of the Pluto system. And the best is yet to come. Most of the data from New Horizons’ closest approach is still onboard the spacecraft. “I predict Charon’s story will become even more amazing!” said Mission Project Scientist Hal Weaver.
What processes are driving the creation of such varied features across Charon and Pluto? That will be a question scientists will tackle in the months and years ahead.