Just one day after NASA's New Horizons spacecraft made its closest approach to distant Pluto, scientists got their first glimpse at images showing that the dwarf planet and its largest moon may both be geologically active.
That has the space agency now searching the data coming back from the space probe for evidence of geysers and volcanoes.
"It's a small world with deep canyons, troughs and cliffs and dark regions that are still mysterious to us," said mission deputy project scientist Cathy Olkin during a news conference. "There is so much interesting science in one image alone.... Pluto did not disappoint. I can add that Charon did not disappoint either."
Alan Stern, New Horizons' principle investigator, was quick to call the first information coming back from New Horizons amazing. "Home run!" he said. "The data look absolutely gorgeous, and Pluto and Charon are just mind blowing."
New Horizons, a piano-sized spacecraft that has been traveling 3 billion miles through the solar system for more than nine years, made its closest approach to Pluto on Tuesday.
On Tuesday night, the spacecraft sent a signal back to Earth that it was functioning well, had traveled its intended path and had collected images and measurements about Pluto and its satellites.
Then early on Wednesday morning, New Horizons began to send back the best images and data on Pluto and its system that anyone has ever seen.
"Pluto New Horizons is a true mission of exploration, showing us why basic scientific research is so important," said John Grunsfeld, associate administrator for NASA's Science Mission Directorate. "The mission has had nine years to build expectations about what we would see during closest approach to Pluto and Charon. Today, we get the first sampling of the scientific treasure collected during those critical moments, and I can tell you it dramatically surpasses those high expectations."
Scientists speaking at Wednesday's news conference also said they believe the mountains on Pluto are made up of ice.
"Water ice at Pluto temperatures is strong enough to hold up huge mountains and that's what I think we're seeing here," said, John Spencer, one of New Horizons' lead scientists. "It's the first time we've seen an icy world that isn't orbiting a giant planet."
According to NASA, the mountains on Pluto likely formed no more than 100 million years ago. That would make them "mere youngsters" in a 4.56-billion-year-old solar system.
That suggests, the space agency noted, the region may still be geologically active today.
"These very small planets can be very active after a long time," said Stern. "It's going to send geophysicists back to the drawing board to figure out how they do that."
Charon, the largest of Pluto's known moons, also shows signs of geological activity.
A 600-mile-long area of cliffs and troughs is leading scientists to believe there has been a widespread fracturing of Charon's crust, which could very well be the result of internal geological processes.
NASA researchers noted that this is just the first taste of the information that they expect to come pouring back from New Horizons about Pluto and its system.
The space agency plans to have another news conference on Friday to offer up more information, including measurements of Pluto's atmosphere and possibly information on the dwarf planet's four other moons -- Nix, Hydra, Styx and Kerberos.
New Horizons, which was designed, built and operated by Johns Hopkins University, uses seven instruments, including an infrared imager; an ultraviolet spectrometer that analyzes Pluto's atmosphere; and a telescopic camera.
The new images are expected to be 10 times higher in resolution than previous images the probe sent back as it approached Pluto.
On Tuesday, NASA administrator Charles Bolden called New Horizons' flyby of Pluto a historic accomplishment, noting that with this mission NASA spacecraft have visited every planet in the solar system.