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Pluto's famous heart powers icy winds on the dwarf planet

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By Mike Wall
published

The heart is pumping nitrogen-dominated air around Pluto.

The left lobe of Pluto's heart-shaped feature is a 600-mile-wide (1,000 kilometers) ice plain known as Sputnik Planitia.
The left lobe of Pluto's heart-shaped feature is a 600-mile-wide (1,000 kilometers) ice plain known as Sputnik Planitia. (Image credit: NASA/JHUAPL/SwRI)

Pluto's icy heart is beating.

The dwarf planet's famous heart-shaped feature, which NASA's New Horizons spacecraft discovered during its epic July 2015 flyby, drives atmospheric circulation patterns on Pluto, a new study suggests.

Most of the action comes courtesy of the heart's left lobe, a 600-mile-wide (1,000 kilometers) nitrogen-ice plain called Sputnik Planitia. This exotic ice vaporizes during the day and condenses into ice again at night, causing nitrogen winds to blow, the researchers determined. (Pluto's atmosphere is dominated by nitrogen, like Earth's, though the dwarf planet's air is about 100,000 times thinner than the stuff we breathe.)  

Related: Destination Pluto: NASA's New Horizons mission in pictures

These winds carry heat, particles of haze and grains of ice westward, staining the ices there with dark streaks.

"This highlights the fact that Pluto's atmosphere and winds — even if the density of the atmosphere is very low — can impact the surface," study lead author Tanguy Bertrand, an astrophysicist and planetary scientist at NASA's Ames Research Center in California, said in a statement. 

And that westward direction is interesting in itself, considering that Pluto spins eastward on its axis. The dwarf planet's atmosphere therefore exhibits an odd "retrorotation," study team members said.

Bertrand and his colleagues studied data gathered by New Horizons during the probe's 2015 close encounter. The researchers also performed computer simulations to model Pluto's nitrogen cycle and weather, especially the dwarf planet's winds.

This work revealed the likely presence of westerly winds — a high-altitude variety that races along at least 2.5 miles (4 kilometers) above the surface and a fast-moving type closer to the ground that follows Sputnik Planitia's western edge.

That edge is bounded by high cliffs, which appear to trap the near-surface winds inside the Sputnik Planitia basin for a spell before they can escape to the west, the new study suggested.

"It's very much the kind of thing that's due to the topography or specifics of the setting," planetary scientist Candice Hansen-Koharcheck, of the Planetary Science Institute in Tucson, Arizona, said in the same statement. 

"I'm impressed that Pluto's models have advanced to the point that you can talk about regional weather," added Hansen-Koharcheck, who was not involved in the new study.

New Horizons' Pluto flyby revealed that the dwarf planet is far more complex and diverse than anyone had thought, featuring towering water-ice mountains and weird "bladed" terrain in addition to the photogenic heart (whose official name, Tombaugh Regio, honors the discoverer of Pluto, Clyde Tombaugh).

The new study, which was published online Tuesday (Feb. 4) in the Journal of Geophysical Research: Planets, reinforces and extends that basic message.

"Sputnik Planitia may be as important for Pluto's climate as the ocean is for Earth's climate," Bertrand said. "If you remove Sputnik Planitia — if you remove the heart of Pluto — you won't have the same circulation."

Mike Wall's book about the search for alien life, "Out There" (Grand Central Publishing, 2018; illustrated by Karl Tate), is out now. Follow him on Twitter @michaeldwall. Follow us on Twitter @Spacedotcom or Facebook. 

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Mike Wall
Mike Wall
Space.com Senior Writer
Michael was a science writer for the Idaho National Laboratory and has been an intern at Wired.com, The Salinas Californian newspaper, and the SLAC National Accelerator Laboratory. He has also worked as a herpetologist and wildlife biologist. He has a Ph.D. in evolutionary biology from the University of Sydney, Australia, a bachelor's degree from the University of Arizona, and a graduate certificate in science writing from the University of California, Santa Cruz.
1 Comment Comment from the forums
  • Hartmann352
    From: Pluto's famous heart powers icy winds on the dwarf planet
    "If you remove Sputnik Planitia — if you remove the heart of Pluto — you won't have the same circulation."

    From - Pluto's Beating Heart Regulates the Atmospheric Circulation: Results From High-Resolution and Multiyear Numerical Climate Simulations by T. Bertrand, F. Forget, O. White, B. Schmitt, et al

    "Runaway albedo and volatile variations and differential condensation and sublimation have been suggested to explain these features (Earle et al., 2018; Moore et al., 2018; White et al., 2017), but the role of atmospheric circulation may be crucial and remains to be explored. Besides, the observations of wind streaks and eolian linear dunes on Pluto's surface (Stern et al., 2015; Telfer et al., 2018) are indications that Pluto's atmospheric dynamics can impact the surface geology."

    After reading both articles it becomes quite clear that Pluto's heart, observable in visible light as a clearly seen heart shaped surface icon, clearly acts as a regulator in Pluto's atmospheric circulation, small as it is by Earth standards, and the clearly delineated wind streaks and linear dunes are evidence of these atmospheric activities.

    Before the New Horizons Mission, Pluto was merely a collection of pixels at the very edge of our solar system where it and its moon, Charon, orbited around a central point. Now, following New Horizon's flyby, Pluto is seen as an incredibly dynamic dwarf planet with a tenuous atmosphere, winds, dunes and a heart controlling it all. Amazing.
    Reply