The giant mysterious hexagon surrounding Saturn’s North Pole now has one more mystery.
NASA’s Cassini spacecraft orbiting Saturn noticed the peculiar change at the planet’s north pole: the giant hexagon surrounding it has changed color.
Scientists have known about Saturn’s hexagon since the Voyager missions in the early 80s. The huge six-sided cloud pattern is believed to be caused by a semi-permanent hurricane located at the planet’s north pole. The hurricane creates a six-sided jet stream that produces the hexagon.
The hexagon has been studied extensively by the Cassini mission, which has been orbiting Saturn since 2004. Recently, footage from Cassini shows that the hexagon has changed color from blue to gold.
Cassini scientists suspect the change was caused by increased sunlight hitting Saturn’s north pole. This increased sunlight causes more production of photochemical hazes that result in the golden color.
That increased sunlight is due to Saturn’s current position in its orbit. In other words, Saturn is changing seasons. It’s springtime for Saturn, and spring means a bright golden color in its northern hemisphere.
Saturn’s orbit takes 29 years to complete, so each season lasts about seven years. Cassini has been observing Saturn in winter, so it has only ever seen the blue color that Saturn takes during those seasons. But ever since Saturn’s spring solstice in August 2009, the planet has been warming up.
Saturn is due to reach its summer solstice in May of next year, and at that point the planet’s long, seven-year summer will begin. If the NASA scientists are right, Saturn may get even more golden in the coming years.
This article was originally written for and published by Popular Mechanics USA.