Fig (1)
The image, obtained by the Saturn-bound Cassini spacecraft image, shows Saturn’s giant active storm.
The storm is visible as a yellowish plume, extending horizontally above center.
Credit: NASA/JPL-Caltech/Space Science Institute   

NASA recently published a breathtaking image of Saturn (fig (1)), acquired by the Saturn-orbiting Cassini spacecraft. The image shows a gigantic storm, churning through Saturn's northern hemisphere. The storm is visible as a curious, plume-like yellowish feature, extending horizontally, above image’s center. The shadows cast by Saturn's rings appear as dark stripes, stretching on the planet’s orb.

This picture was obtained on 25 February 2011, nearly three months after the start of the storm. By this time, the storm’s clouds had formed a bluish tail-shaped formation that encircled its planet.

This energetic storm is the largest, most intense Saturnian storm, in the last three decades. Scientists have found it dwarfs the largest storms of the southern hemisphere of Saturn, observed earlier by Cassini.

The storm is a powerful source of radio waves, which are emitted by lightning, blazing deep in Saturn's atmosphere. This lightning is produced in water clouds, where falling rain and hail generate electricity.

Huge Saturnian storms, known as Great White Spots, as they appear as big white patches, have been observed previously, usually taking place during Saturn’s northern summer. Scientists are puzzled by the scarcity of Saturn’s storms (Saturn’s year is 30 Earth years long, and the Saturnian summer lasts over 28 terrestrial years). It seems that Saturn stores energy, in its atmosphere, for decades, then releases it all at once. This strange pattern of storms is unlike that of Earth or Jupiter, which feature numerous storms, raging throughout the year.

This view looks toward the sunlit side of the rings, from just above the rings’ plane. Images taken using red, green and blue filters were combined, to produce this natural color view. The images were acquired with the Cassini spacecraft wide-angle camera, at a distance of approximately 2.2 million km from Saturn.

References

NASA’s Photojournal
Wikipedia

Aymen Mohamed Ibrahem
Senior Astronomy Specialist