The unique six-sided jet stream called the hexagon around Saturn’s north pole has been caught in high-resolution images by NASA’s Cassini spacecraft, the space agency announced on Wednesday.
NASA has created a movie using the images, which is said to be the first of its kind to show a complete view of the top of Saturn. The hexagon is a wavy jet stream of 200-mph winds with a massive, rotating storm at the center. The spin generated by the storm system is about 20,000 miles across, and according to scientists, no weather feature like this can be found 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,” Andrew Ingersoll, a Cassini imaging team member at the California Institute of Technology in Pasadena, Calif., said in statement. “A hurricane on Earth typically lasts a week, but this has been here for decades -- and who knows -- maybe centuries.”
While storms on Earth are interrupted by friction from land or ice caps, the hexagonal storm is believed to have remained stable, thanks to the lack of solid land forms on Saturn, which is a giant ball of gas.
According to NASA, Cassini obtained high-resolution images of the hexagon over a 10-hour time span, allowing scientists to have a better look at the motion of cloud structures within the storm.
Scientists noticed small vortices rotating in the opposite direction of the hexagon, with the largest of these vortices spanning about 2,200 miles, which is approximately twice the size of the largest hurricane recorded on Earth.
“The hexagonal jet stream is acting like a barrier, which results in something like Earth's Antarctic ozone hole,” Kunio Sayanagi, a Cassini imaging team associate at Hampton University in Virginia, said in the statement.
On Earth, scientists said that the Antarctic ozone hole forms within a region enclosed by a jet stream with similarities to Saturn’s hexagon. During the winter season, ozone-destroying chemical processes occur and the jet stream prevents a resupply of ozone from the outside. As for Saturn, large aerosols that are created when sunlight shines on the atmosphere cannot cross into the hexagonal jet stream from outside.
"As we approach Saturn's summer solstice in 2017, lighting conditions over its north pole will improve, and we are excited to track the changes that occur both inside and outside the hexagon boundary," Scott Edgington, Cassini deputy project scientist at NASA, said.