Pluto’s Undulating Haze, Spinning Moons, & Other Weirdness
published during a full moon.
04/21/2016
undulating haze

Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

It’s already millions of miles away from Pluto, but New Horizons’ revelatory research is still trickling in from its flyby last summer. The mission’s team recently unveiled an animation of Pluto’s atmospheric layers, which hint that the dwarf planet may have gravity waves like on Earth and Mars.

While the layers got brighter and darker, NASA reports that the height of them from the surface stayed the same during the five hours that backlit observations were captured. That points to buoyancy waves, or when air passes over a large obstruction like mountains — a potentially crucial clue to blueprinting Pluto’s atmosphere. (Side note: Gravity waves are not the same as gravitational waves, which you may have read about earlier this year. For more on those, you can read our handy breakdown).

As New Horizons continues on its billion-mile trajectory through the Kuiper Belt toward its new object of affection and flyby target, 2014 MU69, here are some other things we’ve learned about Pluto:

Its atmosphere is mostly nitrogen. 

While the haze is possibly grey or red, its particles actually scatter blue light, meaning Pluto likely has blue skies. These tiny particles are called tholins, and scientists think they form high in the atmosphere, and they’re believed to be responsible for Pluto’s rosy complexion.

undulating haze

Credit: NASA/JHUAPL/SwRI

Pluto may have ice volcanoes.

A couple of Pluto’s mountains could actually be cryovolcanoes that spew a slushy of water ice, nitrogen, ammonia, or methane, as seen on recent 3D topographic maps. The thing that tipped off the team: holes in the mountains’ summit, which on Earth means volcanoes. A study revealed that Pluto is also riddled with thousands of craters varying in size, suggesting Pluto has been surprisingly active throughout its life.

undulating haze

The frozen canyons of Pluto’s North Pole. Credit: NASA/JHUAPL/SwRI

And its moons spin like tops.

Pluto’s main moon squeeze, Charon, is spherical. But its four others — Styx, Nix, Kerberos, and loopy Hydra, the blue moon in the video above — are bright, elongated, and rotate quickly, according to a recent study published in Science.

Pluto’s family is thought to be about 4 billion years old. After comparing the density of each moon’s craters, researchers found that their surfaces have remained relatively untouched since their formation. Along with evidence that some of the moons are smaller bodies melded together, the results support the hypothesis that the small satellites formed in the aftermath of a massive collision that created the Pluto-Charon binary system.