Video: NASA releases high-rez pic of pluto’s big moon

NASA’s New Horizons spacecraft has sent the best colour and the highest resolution images yet of Pluto’s largest moon, Charon, the U.S. space agency announced this week. And the pictures show a surprisingly complex and violent history.

“At half the diameter of Pluto, Charon is the largest satellite relative to its planet in the solar system,” NASA said in a news release.

Many New Horizons scientists expected Charon to be a monotonous, crater-battered world; instead, they’re finding a landscape covered with mountains, canyons, landslides, surface-colour variations and more.

“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 team from the SETI Institute and NASA Ames Research Center in Mountain View, Calif. “But I couldn't be more delighted with what we see."

The high-resolution images of the Pluto-facing hemisphere of Charon were taken by New Horizons as the spacecraft sped through the Pluto system on July 14 and transmitted to Earth on Sept. 21. They reveal details of a belt of fractures and canyons just north of the moon’s equator that stretch more than 1,600 kilometres across the entire face of Charon and likely around onto Charon’s far side.

Four times as long as the Grand Canyon, and twice as deep in places, these faults and canyons indicate a titanic geological upheaval in Charon’s past, NASA said in the release
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“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, Colo.

“With respect to its size relative to Charon, this feature is much like the vast Valles Marineris canyon system on Mars.”

The team also discovered that the plains south of the Charon’s canyon — informally referred to as Vulcan Planum — have fewer large craters than the regions to the north, indicating that they are noticeably younger. The smoothness of the plains, as well as their grooves and faint ridges, are clear signs of wide-scale resurfacing.

One possibility for the smooth surface is a kind of cold volcanic activity, called 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.

Even higher-resolution Charon images and composition data are still to come as New Horizons transmits data, stored on its digital recorders, during the next year.

When that happens, “I predict Charon’s story will become even more amazing,” said mission Project Scientist Hal Weaver, of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.

The New Horizons spacecraft is currently five billion kilometres from Earth, with all systems healthy and operating normally, NASA said.
For more information and images, visit NASA.gov/newhorizons and http://pluto.jhuapl.edu.