Saturn’s Mysterious North Pole Hexagon

By B.G. Medul on Tuesday, December 10, 2013
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“I came into the world under the sign of Saturn—the star of the slowest revolution, the planet of detours and delays.” —Walter Benjamin, Aesthetics and Politics

In A Nutshell

When we talk of space, we almost instantly think of globes and spheres and random-shaped debris floating around. So it came as a surprise when scientists discovered what seems to be a giant hexagon cloud formation at Saturn’s north pole. Apparently, the gas giant has more to offer than just its infamous rings, but no one is really certain what is causing the weather pattern.

The Whole Bushel

Saturn’s north pole hexagonal weather pattern was first observed when scientist combined the images captured by Voyager spacecrafts in the Saturn flyby missions in the early 1980s. It is a rotating cloud formation about 24,000 kilometers (15,000 mi) across. The sides of the hexagon are estimated at about 14,000 kilometers (8,600 mi) in length. Basically, it is a giant storm that can envelope four Earths inside. Another spacecraft, the Cassini, orbited and observed Saturn since 2004 but only thermal and infrared images were available then until the 15-year Saturnian dark winter ended and the springtime came in 2009.

Higher-resolution images from the Cassini spacecraft revealed that the hexagon goes down deep into the atmosphere, some 95 kilometers (60 mi) below the visible clouds from space and houses many smaller storms and a local cloud system inside. The sides of the hexagon are walls and jet streams of wind going as fast as 325 kilometers per hour (200 mph). Other features observed are concentric circles and a giant vortex in the middle not unlike Jupiter’s Great Red Spot. From the images, it appears that it has a rotational period the same as Saturn’s, a little over 10 hours and 30 minutes.

The reason for the existence of the hexagon still baffles scientists up to this date. Answers regarding the driving conditions that force the streams to form the walls are still unclear. It is also unclear how the winds maintain their momentum at such weird motion track, and ultimately, how and when the hexagon will fade from the planet’s surface. It seems that after the first time Voyager caught a glimpse of it, it still remains constant with the rotational pattern of the planet. It is significantly unchanged 30 years it was first photographed. Since it was only observed recently, we don’t know if it persisted longer than the famed Red Spot (the Great Red Spot was first observed in 1831). Saturn’s tilt relative to Earth, the 30-year-long revolution around the Sun, and the long winter nights kept the shape from our curious telescopes, so it is always necessary to employ a spacecraft like the Cassini to orbit directly above the pole.

What is notable about this formation is that the opposite pole of Saturn has an entirely different cloud pattern. On its south pole lies a great storm with what appears to be an enormous eye.

There is no other planet in the solar system that has this kind of display. Currently, scientists are still exploring the characteristics of the structure. They are presently into observing the waves that are created when the wind streams hit the hardest at the corners of the hexagon. They are also looking into a dark spot that shifts position inside the perimeter. Saturn’s hexagon is one of the few natural hexagon-shaped objects known, joining honeycomb, snowflakes, rare cloud formations, and possibly some diatoms.

Show Me The Proof

NASA: Unlocking Saturn’s Secrets
Saturn’s Hexagon — One of the Most Bizarre Things Seen in the Solar System
Saturn’s Hexagonal Storm: What’s Going On?
Photo Credit: NASA/JPL-Caltech/Space Science Institute