There are blue skies on Pluto, NASA says
The first images of Pluto's atmospheric hazes sent back by the New Horizons spacecraft show that mornings there might not be so different from Earth's -- in at least one way.
- Finalist for the Nesta Tipping Point prize and a degree in broadcast journalism from the University of Missouri-Columbia.
You've probably had the experience of seeing a beautiful blue sky early in the morning and being humbled by how vibrant and awesome the lively planet beneath that atmosphere is. As it turns out, you might be greeted by a similar sky if you awoke on Pluto instead of Earth.
While the images of Pluto sent back by NASA's New Horizons spacecraft this year show a planet that's definitely more frozen than lively, it does appear to be more vibrant and colorful than most of us probably expected. On Thursday, NASA shared the first color images of the dwarf planet's atmospheric hazes, and they're a gorgeous kind of cobalt blue.
"That striking blue tint tells us about the size and composition of the haze particles," New Horizons science team researcher Carly Howett said in a release. "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 -- sootlike particles we call tholins."
"Tholins" is actually a pretty broad term for complex organic solids found in some interesting places around the solar system, like Titan, Triton and now Pluto. The name was coined by none other than Carl Sagan in 1979, and according to Sarah Hörst of Johns Hopkins University, the particles can affect habitability on a planet by blocking nasty UV photons in the atmosphere. They can also become a source of organic material when they make it to the surface.
That's potentially good news for those looking to speculate on Pluto as a 24th-century tourist destination.
While they scatter blue light similar to the way nitrogen gives us our azure ceiling, the tholin particles are probably really gray or red, possibly explaining the brown and reddish hues seen on Pluto's surface.
Before you pack your bags for the Kuiper Belt, though, keep in mind that Pluto is still really damn cold and icy. In fact, the New Horizons team says some of the red areas of Pluto's surface could actually be water ice (versus ice made of methane, nitrogen, carbon monoxide or other frozen compounds seen in the outer solar system). The spacecraft detected a number of small areas where water ice is exposed, including in regions that appear bright red in the images of the planet we've seen.
"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."
All the more reason to plan a trip there, especially since there'd be blue skies smiling at us...nothing but blue skies.