Scientists have known of an immense ring orbiting planet Saturn but a new study has revealed that this giant ring, discovered in 2009 with the aid of the Spitzer Space Telescope, is larger than previously thought.

The ring known as Phoebe ring is made up of dark grains of dust that are likely debris from the gas giant's moon Phoebe. Astronomers have found that it is so large it spans an area of space almost 7,000 times larger than the ringed planet itself.

The Phoebe ring was previously believed to span between 7.7 million to 12.4 million kms from Saturn but observation by the U.S. space agency's Wise spacecraft revealed that this extends between six million and 16.2 million kms, or 30 percent more than earlier thought. The researchers said that the estimates are even conservative and that the ring span could be more.

"The ring was detected between distances of 128 and 207 Saturn radii (RS = 60,330 kilometres) from the planet, with a full vertical extent of 40RS," Planetary scientist Douglas Hamilton, from the University of Maryland, and colleagues wrote in their report on Saturn's Phoebe ring, which was published in the journal Nature on June 10. "Here we report infrared imaging of the entire ring, which extends from 100RS out to a surprisingly distant 270RS."

Besides the enormous Pheobe ring, Saturn also has a number of other interesting features. The planet is composed mostly of hydrogen and helium. It is also aptly described as a giant because it is large enough it can hold over 760 planets the size of Earth. It is also more massive than any other planet in the Solar System except Jupiter having about 95 times the mass of the Earth.

The gas planet, however, has the lowest density being less dense than water. If it could be placed in a giant bathtub, the ringed planet would float.

While Earth only has one moon, Saturn has 150 moons and moonlets, all of which are frozen worlds. Of these, the largest are Rhea and Titan, which is bigger than Mercury and known to be the second-largest moon in the Solar System.

Although Saturn is notable for its stunning rings, it is not the only planet with this feature. Neptune, Uranus and Jupiter also have rings albeit these are fainter and not as spectacular when compared with those of Saturn's.