
© NASA
Saturn's polar hexagon changes color from 2012 to 2016.
It's like nothing we've seen on any other planet in the entire Universe, and now the mysterious structure on Saturn's north pole just got even weirder.
In just four years, Saturn's hexagon has
changed its colour from blue to gold. So far, our best guess as to why this change occurred is that this is what it looks like when Saturn's north pole gears up for next year's summer solstice.
Discovered almost 30 years ago,
Saturn's hexagon is a six-sided structure that spans roughly 32,000 km (20,000 miles) in diameter, and extends about 100 km (60 miles) down into the planet's dense atmosphere. As observed by NASA's Voyager and Cassini spacecraft, each point of the hexagon appears to rotate at its centre at nearly the same rate that Saturn rotates on its axis. Along the rim of the hexagon, a jet stream of air is blasting eastward
at speeds of 321 km/h (200 mph).

© NASA
Based on its size and movements, scientists have concluded that it's
a vast cloud pattern generated by a gigantic, perpetual hurricane spinning at the centre of the planet's north pole. Scientists estimate that this storm has been raging for decades -
maybe even centuries.
While we're pretty confident that we know what Saturn's hexagon is,
the big mystery is how it got there in the first place. Once you have a giant whirlpool of air, it's relatively easy to keep it spinning - but the force you need to get it wound up in the first place is a whole lot more difficult to explain. "Scientists have bandied about a number of explanations for the hexagon's origin," says Charles Q. Choi from Space.com. "For instance, water swirling inside a bucket can generate whirlpools possessing holes with geometric shapes. However, there is of course no giant bucket on Saturn holding this gargantuan hexagon."
Now we've got something else to explain - how the Cassini spacecraft could have observed two completely different colours in the hexagon between November 2012 and September 2016. Here's more of the false colour hexagon:
Comment: Are these satellites just falling to pieces because of bad design? Is someone using them as target practice? Or are some of them falling victim to the increase in space rocks penetrating our skies? (For example: Space rock collision? USAF satellite explodes in Earth orbit) What exactly are these satellites used for? From Lockheed: