NASA's New Horizons spacecraft had several discoveries, just a day after its historic Pluto flyby, the mission team said on Wednesday.

The spacecraft sent back the first close-up images, including icy mountains on Pluto and a new, crisp view of its largest moon, 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," John Grunsfeld, associate administrator of the U.S. space agency NASA, said in a statement.

"The mission has had nine years to build expectations about what we would see during closest approach to Pluto and Charon," said Grunsfeld.

A new close-up image of an equatorial region near the base of Pluto's bright heart-shaped feature shows mountains rising as high as 3,500 meters from the surrounding terrain.

The mountainous terrain shown in the image must have been created no more than 100 million years ago, mere youngsters in a 4.56-billion-year-old solar system.

Another image released Wednesday shows Pluto's moon, Charon, in unprecedented detail.

According to NASA, the new view of Charon reveals a youthful and varied terrain. Scientists are surprised by the apparent lack of craters. A swath of cliffs and troughs stretching about 1,000 kilometers suggests widespread fracturing of Charon's crust, likely the result of internal geological processes.

The image also shows a canyon estimated to be 7 to 9 km deep. In Charon's north polar region, the dark surface markings have a diffuse boundary, suggesting a thin deposit or stain on the surface.

What's more, New Horizons also observed the smaller members of the Pluto system, which includes four other moons: Nix, Hydra, Styx and Kerberos.

"New Horizons is returning amazing results already. The data look absolutely gorgeous, and Pluto and Charon are just mind blowing, " said Alan Stern, principal investigator for New Horizons.