<P> The oval object rotates counter-clockwise, with a period of about six Earth days or fourteen Jovian days . Measuring in at 10,159 miles (16,350 kilometers) in width (as of April 3, 2017) Jupiter's Great Red Spot is 1.3 times as wide as Earth . The cloud - tops of this storm are about eight kilometres above the surrounding cloud - tops . </P> <P> Infrared data have long indicated that the Great Red Spot is colder (and thus, higher in altitude) than most of the other clouds on the planet . However, recent infrared measurements of the upper atmosphere show far more heat above the Great Red Spot than the rest of the planet; "acoustic waves" rising from the storm have been proposed as an explanation for Jupiter's temperature . </P> <P> Careful tracking of atmospheric features revealed the spot's counter-clockwise circulation as far back as 1966, observations dramatically confirmed by the first time - lapse movies from the Voyager fly - bys . The spot is confined by a modest eastward jet stream to its south and a very strong westward one to its north . Though winds around the edge of the spot peak at ~ 120 metres per second (432 kilometres per hour), currents inside it seem stagnant, with little inflow or outflow . The rotation period of the spot has decreased with time, perhaps as a direct result of its steady reduction in size . </P> <P> The Great Red Spot's latitude has been stable for the duration of good observational records, typically varying by about a degree . Its longitude, however, is subject to constant variation . Because Jupiter does not rotate uniformly at all latitudes, astronomers have defined three different systems for defining the longitude . System II is used for latitudes of more than 10 °, and was originally based on the average rotation rate of the Great Red Spot of 9h 55m 42s . Despite this, however, the spot has "lapped" the planet in System II at least 10 times since the early nineteenth century . Its drift rate has changed dramatically over the years and has been linked to the brightness of the South Equatorial Belt, and the presence or absence of a South Tropical Disturbance . </P>

How fast are the winds in the great red spot on jupiter