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It seems like Earth isn’t the only place you’ll find a blue sky in our solar system.

New Horizons investigators have found that the haze around Pluto is blue.

“Who would have expected a blue sky in the Kuiper Belt? It’s gorgeous,” said Alan Stern, New Horizons principal investigator from Southwest Research Institute (SwRI), Boulder, Colorado.

The particles themselves are likely grey or red, but the way they scatter light creates the blue sky.

“A blue sky often results from scattering of sunlight by very small particles,” said science team researcher Carly Howett of SwRI. “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.”

Another exciting find from New Horizon’s data has been the presence of small regions of water ice (rather than other types of ice such as carbon dioxide ice, for example).

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Regions with exposed water ice are highlighted in blue in this composite image from New Horizons’ Ralph instrument, combining visible imagery with infrared spectroscopy. NASA/JHUAPL/SwRI

“Large expanses of Pluto don’t show exposed water ice,” said science team member Jason Cook, of SwRI, “because it’s apparently masked by other, more volatile ices across most of the planet. Understanding why water appears exactly where it does, and not in other places, is a challenge that we are digging into.”

Pluto continues to provide plenty of mysteries for scientists.

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