NASA unveiled its first true-color, close-up portrait of Pluto on Friday, revealing a surprisingly active world awash in glaciers of nitrogen and methane ice that overflow into ancient impact craters and lap against mountain scarps.

The color image was among the latest transmitted from the New Horizons spacecraft this week, which is now leaving the dwarf planet behind at the speed of 10 miles per second. Only a fraction of the data it collected as it flew past Pluto 10 days ago has reached researchers on Earth so far, but it was enough Friday to make some scientists choke back tears.

“It’s turned out to be a scientific wonderland,” said Alan Stern, principal investigator for the $720 million mission, from the Southwest Research Institute in Boulder, Colo. The mission scientists presented the new findings at a news briefing Friday in Washington, D.C.

As the spacecraft left Pluto behind, it also captured the first image of the small world’s atmosphere backlit by the sun. In the dramatic silhouette, the scientists could detect ripples of haze and fogs of hydrocarbons that extend up to 80 miles or so above the surface. They speculated that, as the dwarf planet moves away from the sun on its orbit, the haze may condense into snowfalls that could give Pluto’s surface a faint reddish hue.

“This is our peek at weather in Pluto’s atmosphere,” said mission scientist Michael Summers from George Mason University in Fairfax, Va., who studies planetary atmospheres. “This is pretty astonishing, at least to an atmospheric scientist.”