NASA Cassini spacecraft obtains best views of Saturn hexagon

This colourful view from NASA's Cassini mission is the highest-resolution view of the unique six-sided jet stream at Saturn's north pole known as "the hexagon." 

This movie, made from images obtained by Cassini's imaging cameras, is the first to show the hexagon in colour filters, and the first movie to show a complete view from the north pole down to about 70 degrees north latitude. 

Credit: NASA/JPL-Caltech /SSI/Hampton

NASA's Cassini spacecraft has obtained the highest-resolution movie yet of a unique six-sided jet stream, known as the hexagon, around Saturn's north pole.

This is the first hexagon movie of its kind, using color filters, and the first to show a complete view of the top of Saturn down to about 70 degrees latitude.

Spanning about 20,000 miles (30,000 kilometers) across, the hexagon is a wavy jet stream of 200-mile-per-hour winds (about 322 kilometers per hour) with a massive, rotating storm at the center.

There is no weather feature exactly, consistently like this anywhere else in the solar system.

"The hexagon is just a current of air, and weather features out there that share similarities to this are notoriously turbulent and unstable," said Andrew Ingersoll, a Cassini imaging team member at the California Institute of Technology in Pasadena.

"A hurricane on Earth typically lasts a week, but this has been here for decades—and who knows—maybe centuries."

Weather patterns on Earth are interrupted when they encounter friction from landforms or ice caps.

Scientists suspect the stability of the hexagon has something to do with the lack of solid landforms on Saturn, which is essentially a giant ball of gas.

Better views of the hexagon are available now because the sun began to illuminate its interior in late 2012.

Cassini captured images of the hexagon over a 10-hour time span with high-resolution cameras, giving scientists a good look at the motion of cloud structures within.

This infrared movie from NASA's Cassini mission shows the churning of the curious six-sided jet stream at Saturn's north pole known as "the hexagon."

The movie, which was sped up here, covers 2 hours and 45 minutes in real time. It was made from data obtained by Cassini's visual and infrared mapping spectrometer in the 5-micron wavelength of radiation. 

This channel shows clouds in silhouette against infrared light emanating from Saturn's interior.

These clouds are composed of relatively large particles and are thick, blocking light so they appear dark.

These kinds of clouds tend to lie deep in Saturn's atmosphere, at about 3 bars of pressure. 

Image credit: NASA/JPL-Caltech/University of Arizona

They saw the storm around the pole, as well as small vortices rotating in the opposite direction of the hexagon.

Some of the vortices are swept along with the jet stream as if on a racetrack. The largest of these vortices spans about 2,200 miles (3,500 kilometers), or about twice the size of the largest hurricane recorded on Earth.

Scientists analyzed these images in false colour, a rendering method that makes it easier to distinguish differences among the types of particles suspended in the atmosphere—relatively small particles that make up haze—inside and outside the hexagon.

Read the full article here