30 November 2011
This is an infrared image of Saturn, obtained by NASA’s Cassini spacecraft, in late 2010, showing an early stage of a giant storm that persisted for many months, in Saturn’s dense, turbulent atmosphere. Cassini was approximately 2 million km from Saturn.
NASA/JPL-Caltech/Space Science Institute
Saturn has a dense turbulent atmosphere. In Saturn, winds blow at speeds of over 1,500 km/h, and giant storms are occasionally observed. The Saturnian storms often appear as whitish ovals, floating amid the planet’s pale cloud bands. They are known as the great white spots. In late 2010, NASA’s Saturn-orbiting Cassini spacecraft imaged a new large Saturnian storm, and monitored its evolution, through mid-2011.
Cassini’s detailed observations of the storm now appear on NASA websites. They include a series of true- color and near-true-color images, chronicling the development of the storm.
This sequence of images, acquired by the Cassini spacecraft, documents the evolution of the largest Saturnian storm in 20 years. The images record the start of the storm, in early December 2010, and reveal its rapid development. In August 2011, the storm was encircling the entire planet.
NASA/JPL-Caltech/Space Science Institute
The first record of a great white spot date back to 1876, when American astronomer Asaph Hall used the white spots to determine period of Saturn’s axial rotation. Other remarkable white spots were imaged by NASA’s Hubble Space Telescope in 1990 and 1994.
Cassini was launched toward Saturn in October 1997. It arrived at Saturn, and entered orbit around it, in July 2004. The Cassini mission to Saturn is one of the greatest and most successful space projects. Cassini has obtained numerous images of Saturn and its moons, and conducted numerous startling discoveries that revolutionized scientists’ understanding of the giant wonderful planet and its moons. Its mission has been extended to 2017.
References
NASA
NASA’s Photojournal
Wikipedia
Further Reading
The Cassini Mission Homepage
http://saturn.jpl.nasa.gov
The Hubble Space Telescope
http://hubblesite.org/
Aymen Mohamed Ibrahem
Senior Astronomy Specialist