Saturn’s six-sided cloud pattern gets a close look

New images show particles in the planet’s hexagonally shaped jet stream

SUPER SWIRL  A sharp boundary defines the six-sided cloud pattern that spans about 30,000 kilometers across Saturn’s north pole, as seen in this new false-color image from the Cassini spacecraft.

Hampton University, SSI, JPL-Caltech/NASA

Saturn’s strange six-sided cloud pattern has gotten its day in the sun.

NASA’s Cassini spacecraft snapped the highest-resolution images to date of the planet’s hexagonal jet stream, which fuels swirling, cloudy storms at the planet’s north pole. Because of recent changes in Saturn’s tilt that allowed the sun to shine on the region, astronomers were able to get a better view and understanding of the roughly 30,000-kilometer-wide cloud structure.

Using colored filters, the Cassini team identified large particles, shown in pink, swirling in the planet’s lower atmosphere. Large particles at higher altitudes appear green, and tiny particles higher in the atmosphere appear blue. Those tiny particles define the sharp boundary of the hexagonal jet stream.

While the geometric shape of Saturn’s jet stream seems odd, its existence is not. Earth’s jet stream also forms cloud swirls around the North Pole. However, “Earth is basically really messy,” said Cassini team member Kunio Sayanagi of Hampton University in Virginia during a Google Hangout by NASA’s Jet Propulsion Laboratoryon December 4.

Air currents on Earth jumble up clouds by blowing over continents, mountains and oceans. But gaseous Saturn is free of solid ground, so the six-sided cloud structure persists and has probably been there for decades, possibly centuries.

Ashley Yeager is the associate news editor at Science News. She has worked at The Scientist, the Simons Foundation, Duke University and the W.M. Keck Observatory, and was the web producer for Science News from 2013 to 2015. She has a bachelor’s degree in journalism from the University of Tennessee, Knoxville, and a master’s degree in science writing from MIT.

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