Just a day after the NASA made its closest ever approach to Pluto, new pictures and data were already streaming in. The latest, released Friday, July 17, shows evidence of carbon monoxide ice in the heart region — being called the Tombaugh Regio after Clyde Tombaugh, who discovered Pluto — signified in green on the first image in the slideshow below. (A close-up appears in the second image.)

“This is just a first at Pluto’s plasma environment,” said New Horizons co-investigator Fran Bagenal, in a news release.

Adds Jim Green, NASAs director of Planetary Science, “With the flyby in the rearview mirror, a decade-long journey to Pluto is over — but the science payoff is only beginning.”

On Wednesday, July 15, after the successful Pluto flyby and with crisp images beginning to arrive, Alan Stern, head of the , was all smiles. “I had a pretty good day yesterday. How about you?” he asked at a news conference.

The spacecraft, which neared the dwarf planet Tuesday morning, was already more than a million miles on the other side of Pluto by Wednesday, Stern said. At that point, five of the seven instruments had sent down data, including the best images ever seen of Pluto and its largest moon, Charon, as well as a smaller moon called Hydra.

Stern is clearly enamored. “The Pluto system is something wonderful,” he said. But he’s not the only one getting excited over the new discoveries.

The icy mountains of Pluto. (NASA/JHU APL/SwRI)

Cathy Olkin, a deputy project scientist from the Southwest Research Institute, described what they’ve learned already from getting closer to Pluto’s largest moon. “Charon just blew our socks off,” she said, adding that the team has been abuzz every time a new find comes into focus. For instance, the scientists very quickly noticed troughs and cliffs 600 miles across the moon, and a smooth line that runs east to west that could indicate geological activity. There are also miles-deep canyons.

“It’s a small world with deep canyons, troughs, cliffs, dark regions that are still slightly mysterious to us,” Olkin said, noting that,“Pluto did not disappoint. I can add that Charon did not disappoint either.”

The presentation from John Spencer, also of SwRI, got the most oohs and aahs, though. He revealed the crispest view of Pluto to date, a high-res image that shows the heart of the dwarf planet and 11,000-foot-high icy mountains. The NASA scientists haven’t yet found a single impact crater there either, meaning the mountains are relatively young, at 100 million years old or younger.

“This is one of the we’ve ever seen in the solar system,” said Jeff Moore of the New Horizons team, in a news release.

For all the excitement around these data, Stern is quick to point out there’s much more to come. “Frankly we’re just skimming the top of it,” he said. New Horizons will be transmitting its data well into 2016.

MORE FROM WEATHER.COM: Amazing New Images of Pluto and Its Moons

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)