New Horizons scientists made this false-color image of Pluto using a technique called principal component analysis to highlight the many subtle color differences between Pluto's distinct regions. The image data were collected by the spacecraft’s Ralph/MVIC color camera on July 14 at 11:11 AM UTC, from a range of 22,000 miles (35,000 kilometers). (Credits:NASA/JHUAPL/SwRI)

Diverse dunes, nitrogen ice flows, rocky peaks and valleys that give way to smooth plains: They're all part of the surface of the dwarf planet Pluto, according to newly published images from NASA.

This previously unknown terrain — captured by NASA's New Horizons spacecraft — has sent scientists are “reeling,” the organization said in .

“Pluto is showing us a diversity of landforms and complexity of processes that rival anything we’ve seen in the solar system,” said New Horizons Principal Investigator Alan Stern, of the Southwest Research Institute (SwRI) in Boulder, Colorado, in a NASA press release, dated Sept. 10. “If an artist had painted this Pluto before our flyby, I probably would have called it over the top — but that’s what is actually there.”

Jeff Moore, leader of the New Horizons Geology, Geophysics and Imaging (GGI) team at NASA’s Ames Research Center in Moffett Field, California, echoed this sentiment, describing the surface of Pluto as “every bit as complex as that of Mars.” There's even the potential that the craggy mountains New Horizons revealed are actually huge blocks of water ice.

The mystery lies in the atmosphere: A jumble of geographic features indicates that the dwarf planet's atmosphere may have been much thicker at one time. “It's a head-scratcher,” said William B. McKinnon, a GGI deputy lead from Washington University, St. Louis.

In the slideshow above, these geographic features can be seen along with the highest-quality images of Pluto's atmosphere ever taken. Pluto's largest moon, Charon, has also been revealed to have a varied, complex surface, indicating a “tortured” past for it as well, NASA said.

NASA has said it will release additional images of Charon (Pluto has five moons in total) on Friday, Sept. 11. We'll update the piece with those images as they arrive.

More on the mission can be found at .

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The ESO 3.6-meter telescope at La Silla observatory in Chile, during observations. (ESO/S. Brunier)