Saturn's north-polar hexagon turns with a jet stream.
Cassini repeatedly photographed six straight sides around Saturn's north pole.
The boundary spans roughly thirty thousand kilometers across Saturn's north pole.
Its cloud pattern rotates once in about ten hours.
That rate follows Saturn's atmospheric rotation, not changing sunlight.
Fast winds curve around corners, maintaining a persistent polygonal boundary.
Cassini infrared observations showed the pattern extends below visible cloud tops.
So its crisp edge does not mean a solid storm wall.
It is a jet-stream boundary organizing neighboring cloud motion.
Rotating-fluid laboratory experiments reproduce similar polygonal jet boundaries.
Scientists connect Saturn's rapid rotation and convection to the pattern.
But scientists still cannot explain why exactly six sides persist.
The evidence supports dynamics, not a hidden object beneath.
The contrast is the answer: sharp edges can come from flowing air.
Saturn's hexagon is flowing jet-stream geometry, not carved structure.