New View of Saturn’s Hexagon

NASA's Cassini spacecraft captures new images of the planet's freakish weather system.

Saturn’s giant, north-pole jet stream is known as “the hexagon” for its unusual shape. This image from NASA’s Cassini spacecraft captures the gas giant down to 70° latitude and covers 20,000 miles (35,000km) of its northern hemisphere. Along the hexagon’s boundaries, winds reach 220 mph (322 km/hr), while a massive storm rotates at its center.

This colorful view from NASA's Cassini mission is the highest-resolution view of the unique six-sided jet stream at Saturn's north pole known as "the hexagon." Click here to watch a time-lapse movie of the weather system, the first to show the hexagon in color filters and to show a complete view from the north pole down to about 70 degrees north latitude.
NASA/JPL-Caltech/SSI/Hampton University

While there are many storms in the solar system, there’s nothing exactly like the hexagon. Unimpeded by solid land masses, which interrupt storms’ progress on Earth and usually limit their existence to a few days, Saturn’s hexagon has possibly existed for decades. On Earth, we have hurricanes — a storm that resembles the one at the hexagon’s center — but those are dwarfed by the hexagon’s size.

The new Cassini images not only reveal smaller vortices inside the hexagon, but also the size, shape, and density. The colors chosen for this false-color rendering distinguish between types of particles: inside the hexagon there are fewer large haze particles but more small haze particles, while outside the hexagon, the opposite is true. The striking clarity is due to a 10-hour exposure and Saturn’s northern spring (which began in August 2009). By 2012 the Sun had illuminated more of the gas giant’s north pole than scientists had ever seen.

Some of the smaller vortices rotate in the opposite direction of the hexagon flow and are occasionally swept around by the jet stream. The largest of these spans 2,200 miles (3,500km) — only one-tenth the hexagon’s size but twice the size of the largest hurricane ever recorded on Earth.

For more information, read JPL's press release.

CATEGORIES
News, Solar System

About Emily Poore

Emily Poore, Sky & Telescope's editorial intern, has a bachelor's degree in physics and English literature with a minor in astronomy. She is currently pursuing her master’s in publishing and writing at Emerson College. Find her on Twitter: @PooreWordChoice

4 thoughts on “New View of Saturn’s Hexagon

  1. R. Petrozello

    Saturn’s rotating hexagon reminds me of a demonstration where liquid Helium behaves in a similar manner when spun inside a rotating cylinder.
    Searching on the internet for information about ‘Vortex Formation in Super-fluids, I came across the following web sites.

    Quantized Vorticies: Flow pattern exhibited by Super-fluids
    http://encyclopedia2.thefreedictionary.com/Quantized+vortices
    Rotating Water Gives Rise to Geometric Figures:
    http://news.softpedia.com/news/Rotating-Water-Gives-Rise-to-Geometric-Figures-23640.shtml
    Vortices in Rotating SuperFluids: (more technical info.)
    http://ltl.tkk.fi/~pjh/vortices.htm

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