Cassini images Saturn’s polar hexagon

Saturn’s north pole as seen by Cassini on Dec. 2, 2016. Photo Credit: NASA / JPL-Caltech / Space Science Institute

On Dec. 2, 2016, NASA’s Cassini spacecraft imaged Saturn’s north polar region. Prominently centered around the north pole is the famous hexagonal cloud that is formed as the result of jet stream interactions in Saturn’s atmosphere. A similar hexagon does not exist at Saturn’s south pole.

The hexagon at the north pole was first identified by the Voyager mission in 1981 and has been studied extensively by the Cassini spacecraft.

The leading hypothesis for the north pole hexagon is that it is the result of wind gradients with respect to latitude. Laboratory tests have shown that the formation of polygonal shapes are possible on rotating bodies along boundaries where wind speeds vary. However, polygon formation occurs within a sensitive range of wind speeds and atmospheric viscosity, which could partially explain why a similar hexagon does not exist at the south pole.

The image was captured by Cassini’s wide-angle camera at a distance of approximately 619,000 miles (996,000 kilometers) from Saturn. The image scale is 37 miles (60 kilometers) per pixel. According to NASA, the view in this image looks toward the sunlit side of the rings from about 26 degrees above the ring plane.

The spacecraft is conducting its final observations as part of a “grand tour” before the mission concludes in September of this year (2017).

Tagged: Cassini Jet Propulsion Laboratory NASA Saturn The Range

Paul Knightly

Paul is currently a graduate student in Space and Planetary Sciences at the University of Akransas in Fayetteville. He grew up in the Kansas City area and developed an interest in space at a young age at the start of the twin Mars Exploration Rover missions in 2003. He began his studies in aerospace engineering before switching over to geology at Wichita State University where he earned a Bachelor of Science in 2013. After working as an environmental geologist for a civil engineering firm, he began his graduate studies in 2016 and is actively working towards a PhD that will focus on the surficial processes of Mars. He also participated in a 2-week simluation at The Mars Society's Mars Desert Research Station in 2014 and remains involved in analogue mission studies today. Paul has been interested in science outreach and communication over the years which in the past included maintaining a personal blog on space exploration from high school through his undergraduate career and in recent years he has given talks at schools and other organizations over the topics of geology and space. He is excited to bring his experience as a geologist and scientist to the Spaceflight Insider team writing primarily on space science topics.