New images of Pluto.
U.S. space regulator announced that new images from its New Horizons space probe have revealed that Pluto has blue skies and water ice on its surface.
The Earth-like skies were seen in the first color images of Pluto's atmospheric hazes, which were returned last week by the U.S. probe operated by the National Aeronautics and Space Administration (NASA).
"Who would have expected a blue sky in the Kuiper Belt? It's gorgeous," Alan Stern, New Horizons principal investigator from the Southwest Research Institute (SwRI), said in a statement this week.
Kuiper Belt is the unexplored outer region of the solar system that includes Pluto and potentially thousands of similar icy, rocky small planets.
The haze particles themselves are likely gray or red, said NASA. But their small size and composition may allow them to scatter blue light, in a way similar to what tiny particles are doing on Earth's atmosphere.
"A blue sky often results from scattering of sunlight by very small particles," said science team researcher Carly Howett, also of the SwRI. "On Pluto they appear to be larger -- but still relatively small -- soot-like particles we call tholins."
A similar process has also been found to occur in the atmosphere of Saturn's moon Titan.
In a second significant finding, New Horizons has detected numerous small, exposed regions of water ice on Pluto.
"Large expanses of Pluto don't show exposed water ice because it's apparently masked by other, more volatile ices across most of the planet," said science team member Jason Cook, of the SwRI, "Understanding why water appears exactly where it does, and not in other places, is a challenge that we are digging into."
Curiously, the areas showing the most obvious water ice spectral signatures are bright red in recently released color images.
"I'm surprised that this water ice is so red," said Silvia Protopapa, a science team member from the University of Maryland. "We don't yet understand the relationship between water ice and the reddish tholin colorants on Pluto's surface."
Launched in 2006, the New Horizons spacecraft is currently five billion kilometers from Earth.