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International Edition Winners - 2012: India, Target 2, Grade: 12

International Edition Winners - 2012: India, Target 2, Grade: 12


Heta Patel
Saturn's F ring
Target 2, Saturn's F ring
Heta Patel

Baroda High School, Alkapuri,
12th Grade
Vadodara, Gujarat




"The F-ring: Saturn's craziest ring.

I think we should point Cassini to observe the F-ring. It is the most active rings of Saturn. It is a faint ring on the outer edge of A-ring. It was discovered in 1979 by NASA's Pioneer 11. The rings are known to be made up of icy dust particles. However the origin of the rings is yet to be confirmed. There are two main ideas: they came from a moon that got too close to Saturn (beyond Roche limit) and was torn apart (or hit by another object and fragmented) or can be particles which couldn't form moon when Saturn was first formed which is now ruled out as those particles would have been unstable and diffused in the space by now. Saturn's rings are quite bright and suggest they could not have been there a few hundred million years ago.

The F-ring is not only a beautiful thing to photograph but is also very active. It has two shepherd moons Prometheus and Pandora. Shepherd moon basically means they hold the F-ring in place and keep its particles from wandering off in space. Prometheus orbits between A-ring and F-ring and Pandora on the outer side of F-ring.

Pandora and Prometheus were discovered in October 1980 by voyager 1. Pandora is a potato-shaped moon. The craters on Pandora are not sharp/well defined compared to other moons. They are smoothened which is quite surprising to me. Prometheus is elongated and has number of valleys and craters. It has low density which suggests that it may be a porous icy body. With the help of Cassini we can confirm this.

The F-ring is very intriguing. The images revealed that it has somewhat a "braided" structure, as if thin rings had been wounded around each other. It has a central ring and a wavy ring. It is also suspected that Pandora and Prometheus play a role in the F-rings strange nature. Because of the gravitational field of the moons the ring has kinks and bumps in it, as the moons steal particles from the ring, which is why it appears to be braided.

Another interesting phenomenon is the bright trails or also known as "mini-jets". The moon Prometheus can create ripples/channels or snowballs in the F-ring. Some of these snowballs are broken by collisions but some also survive. These small snowballs go on striking the F-ring. In some cases they move in a group creating beautiful pattern. It is one of the best things for astro-photography.

Hence observing the F-ring with the Cassini can help us to find out about the origin of the rings, which seem be a common trend in bigger planets. Also find out about the surface of F-ring's shepherd moons. And catch some spectacular images of this faint but dynamic ring of Saturn."