Saturn's hexagon change in season. These changes were observed by the Cassini spacecraft. One hypothesis, developed at Oxford University, is that the hexagon forms where there is a steep latitudinal gradient in the speed of the atmospheric winds in Saturn's atmosphere. Similar regular shapes were created in the laboratory when a circular tank of liquid was rotated at different speeds at its centre and periphery. The most common shape was six sided, but shapes with three to eight sides were also produced. The shapes form in an area of turbulent flow between the two different rotating fluid bodies with dissimilar speeds. A
Approach and departure angles Approach and departure angles Approach angle is the maximum angle of a ramp onto which a vehicle can climb from a horizontal plane without interference. It is defined as the angle between the ground and the line drawn between the front tire and the lowest-hanging part of the vehicle at the front overhang. Departure angle is its counterpart at the rear of the vehicle – the maximum ramp angle from which the car can descend without damage. Approach and departure angles are also referred to as ramp angles. Approach and departure angles are indicators of off-road ability of the vehicle: