The Solution to Saturn's G-ring Mystery

Since the time of Galileo Galilee astronomers have been fascinated by the planet Saturn. Galileo himself could not understand why the planet looked so different in the night sky at different times when he gazed into his telescope. We have sinced realized that this is due to the way the planet's rings move about the planet. While scientists have come a long way since the 17^th century, one ring of Saturn baffled most observers, until recently that is.

The behavior of the G-ring around the planet Saturn has been an a mystery to astronomers for many years. Normally rings require the pull of a nearby moon to keep them in orbit around the planet. Without the gravitational interaction with a moon, the particles drift out into space and a ring will not form. Astronomers believed that the planet's G-ring had no such forces acting upon it to keep it in motion.

The Cassini-Huygens, in orbit around the gas giant, revealed that the G-ring does in fact interact with one of the more distant moons of the planet. One sixth of the ring is made up of tightly packed ice particles, the probe revealed. The probe also indicated that the orbit of the rings moon is linked to the moon Minas which completes 6 orbits for every seven of the ring. The findings of the probe were published in Sciene magazine.

The nearby E ring was known to be supplied with material from the nearby Enceladus, while the F ring is probably held together by two of the planets satellites: Pandora and Prometheus. The mystery resulted because the planet's G ring is not near a moon.

"When you get this kind of whole number ratio, there can be some strange things called resonances that occur. These can have interesting influences and can actually confine material within the ring," said Dr Hedman, a research associate at Cornell university.

According to NASA's Jet Propulsion laboratory website the ring is a product of a complex interaction between the moons, the rings, and Saturn's magnetosphere. The Cassini-Huygens space probe was an international effort and entered orbit around Saturn and its moons in 2004. The Huygens probe was launched onto the surface of Titan to collect data.

The probe will be in orbit around the planet for many years to come and send back further data, especially on Titan to see if it's possible that the moon could support primitive forms of life.

Sources:

http://news.bbc.co.uk/2/hi/science/nature/6927965.stm

http://saturn.jpl.nasa.gov/overview/index.cfm