Ice composed of water has been detected on Pluto as NASA's New Horizons probe continues to transmit data and visuals from 3.1 billion miles away.
"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,"
explained Jason Cook, of the Southwest Research Institute (SwRI) in Boulder, Colorado.
"Understanding why water appears exactly where it does, and not in other places, is a challenge that we are digging into," he added.
Much of the ice appears to be located in areas of the dwarf planet that are red, a phenomenon scientists are also currently investigating.
"I’m surprised that this water ice is so red," said Silvia Protopapa, a science team member from the University of Maryland, College Park. "We don’t yet understand the relationship between water ice and the reddish tholin colorants on Pluto's surface."
In referring to "tholins," Protopapa explained that it's currently believed that the soot-like particles form high in the atmosphere, and precipitate down to the surface of Pluto after volatile gases condense and coat their surfaces with ice frost.
The tholins are also believed to contribute to the blue tint seen in the atmosphere around Pluto in recently received photos from the New Horizons probe.
"That striking blue tint tells us about the size and composition of the haze particles," said science team researcher Carly Howett of SwRI. "A blue sky often results from scattering of sunlight by very small particles. On Earth, those particles are very tiny nitrogen molecules. On Pluto they appear to be larger — but still relatively small — soot-like particles we call tholins."
Many celebrated NASA's new batch of Pluto photos on social media.