A colossal, swirling storm with a well-developed eye is churning at Saturn's south pole, the first time a truly hurricane-like storm has been detected on a planet other than Earth, Nasa images showed on Thursday.

The storm on the giant, ringed planet is about 5,000 miles wide, measuring roughly two thirds the diameter of Earth, with winds howling

clockwise at 350 mph (550 kph).

Jupiter's Great Red Spot, which swirls counterclockwise, is far bigger, but is less like a hurricane because it lacks the typical eye and eye wall.

The images -- essentially a 14-frame movie -- were captured over a period of three hours on October 11 by the US space agency's Cassini spacecraft as it passed about 210,000 miles from the planet as part of its exploration of Saturn and its moons.