Saturn’s hexagon is a hexagonal cloud pattern that has persisted at the North Pole of Saturn since its discovery in 1981. At the time, Cassini was only able to take infrared photographs of the phenomenon until it passed into sunlight in 2009, at which point amateur photographers managed to be able to photograph it from Earth.
The structure is roughly 20,000 miles (32,000 km) wide, which is larger than Earth; and thermal images show that it reaches roughly 60 miles (100 km) down into Saturn’s interior.
Read an explanation of how Saturn’s hexagon works here: [x]