Washington, Jan 15: Researchers, using spacecraft observations, have shed new light on the great red spot on Jupiter, showing how the spot – which is inaccurately described as a storm – is actually far calmer than other parts of the planet’s atmosphere.

According to a report in Discovery news, numerical modeling of the spot, as well as laboratory experiments trying to reproduce the dynamics of the Great Red Spot indicate that it is quite different than earlier believed.

"The Red Spot is very quiet at its center," said Jupiter researcher Philip Marcus of the University of California at Berkeley.

In fact, the winds at the center are just 9 or 10 miles per hour, whereas around the perimeter they exceed 200 miles per hour.

"It's telling us something about Jupiter. There must be something special about Jupiter's atmosphere that makes it different," said Marcus.

One thing that stands out about Jupiter's atmosphere is that it has a zig-zag pattern of twelve jet streams which make up its signature pastel-toned bands. Earth, by comparison, has only two jet streams.

The Great Red Spot is sandwiched between two of these jets streams, forcing the winds that power those perimeter winds to deflect around the spot.

But, the location of the Red spot near the equator and the highest speed jet streams suggest that there is some critical speed at which the spot becomes a stable arrangement in the atmosphere.

That speed is due to the little vortices of wind that break off from the perimeter and periodically twirl into the center of the Great Red Spot.

"The Red Spot is trying to disperse, but it keeps eating little high-speed vortices of wind," said Marcus.

What this all means to the planet as a whole is that when the Great Red Spot changes shape or color, it implies something strange is afoot in the atmosphere in general.

"The Red Spot has changed shape dramatically, although its strength hasn't changed," said Marcus.

That implies that something, probably the temperature of Jupiter's atmosphere is changing.

"There have been a lot of changes in Jupiter's atmosphere," said astronomer and planetary scientist Imke de Pater, also at Berkeley.

“And since the only temperatures that can be currently measured are far too high in the Jovian stratosphere to reveal much information, the Great Red Spot is one of the few clues to what is going on,” she added. (ANI)