The hexagon shaped hurricane that occupies the entire north pole of Saturn has fascinated astronomers since it was discovered during the Voyager missions in the early ’80s. About a year ago, the Cassini spacecraft passed above it and, thanks to a favorable sunlight, it was able to take high resolution pictures of this peculiar weather phenomenon. Now NASA has released these photos during a Google+ hangout that had purpose to present them.
Hexagonal structures exist on Earth as well and have even been recreated even in laboratory so they have a scientific explanation. The one on Saturn, however, is truly enormous, spannig 30,000 km (about 20,000 miles) across with winds exceeding 320 km/h (about 200 mph). NASA had already released some pictures taken by the Cassini spacecraft in May 2013 but these new ones were processed with filters that have made ultraviolet and infrared frequencies visible so they’re even better.
The storm at the center and many vortices rotating in the direction opposite to the hexagon are clearly visible. The largest vortices reach a diameter of 3,500 km (about 2,200 miles), twice the largest hurricane ever recorded on Earth. The difference with Saturn’s hexagon hurricane lies not only in its size but also in its life span. Structures of that kind are turbulent and unstable and a hurricane on Earth lasts on average a week. The hexagon on Saturn has existed for over 30 years and who knows when it started.
According to scientists, this life span impossible on Earth could be due to the fact that on our planet currents encounter friction due to the solid surface, especially of hills and mountains. Saturn doesn’t have a solid surface being a gas giant so the lack of the friction existing on Earth probably allows the North Pole hurricane to keep on existing.
In the northern hemisphere of Saturn spring started in 2009. This allowed to have a more and more favorable solar illumination and thus better and better chances for the Cassini spacecraft to take good photographs. The summer solstice will occur in 2017 and at that time the conditions will be optimal. The problem is that the budget for the Cassini mission may not be renewed and its interruption would really be a huge loss.
