By MARCIA DUNN
AP Aerospace Writer
CAPE CANAVERAL, Fla. (AP) - Mankind's first close-up look at Pluto did not disappoint Wednesday: The pictures showed ice mountains on Pluto about as high as the Rockies and canyons on its big moon Charon that appear deeper than those on Earth.
Especially astounding to scientists was the absence of craters in a zoom-in shot of Pluto, the dwarf planet that hosted its first visitor from Earth on Tuesday, NASA's New Horizons spacecraft.
They said that suggests to their surprise that Pluto is geologically active even now and is being sculpted not by outside forces but by internal heat.
The long-awaited images were unveiled Wednesday in Maryland, home to mission operations for NASA's New Horizons spacecraft.
"I don't think any one of us could have imagined that it was this good of a toy store," principal scientist Alan Stern said at a news conference. He marveled: "The Pluto system IS something wonderful."
Added Lowell Observatory's Will Grundy: "This is what we came for."
"This exceeds what we came for," corrected deputy project scientist Cathy Olkin.
The zoom-in of Pluto, showing an approximately 150-mile swath of the planet, reveals a mountain range about 11,000 feet high and tens of miles wide. John Spencer, a planetary scientist at Southwestern Research Institute, said the mountains appeared to be formed from Pluto's icy bedrock.
The canyons on Charon look to be 3 miles to 6 miles deep.
The images were collected as New Horizons swept within 7,700 miles of Pluto on Tuesday, becoming Pluto's first visitor in its 4.5 billion-year existence.
Scientists didn't know until Tuesday night - when the spacecraft phoned home - that the encounter was a success.
New Horizons already is 1 million miles beyond the dwarf planet, and 3 billion miles from Earth.
Johns Hopkins University: http://pluto.jhuapl.edu