BERLIN: The spokes that come and go on Saturn's rings could be the result of thunderstorms in the planet, according to German researchers.
If this perception is correct, the lightning that strikes Saturn could be several thousand times stronger than the thunderstorms that strike Earth and the impact could be that beams of electrons are released from the planet's surface to fall into the rings to create electrically charged dust that is seen as the spokes.
Geraint Jones of the Max Planck Institute for Solar System Research in Katlenburg-Lindau, Germany and his team say the idea appears to be plausible as it fits with the effects of thunderstorms on Earth.
Besides, the theory that the spokes could be the result of strikes by meteorites cannot hold as several meteorites cannot be expected to strike the rings at the same place in close succession, they say.
The team's contention still remains in theory as there is no proof of storm-induced electron beams on Saturn. According to the publication Nature, the spokes are transient, building up over a period of a few hours and disappearing several hours later.
The spokes were first identified by the Voyager I and II spacecraft as they passed close to the planet in 1980 and 1981. They appear as bright or dark streaks several kilometers wide and thousands of kilometers long that cross the rings. They are not present always.
For example, when NASA's Cassini spacecraft first viewed the planet, these were not there. However, when the spacecraft took pictures of the planet in September 2005, they were present.
While researchers strongly feel this spokes could be made of electrically charged dust grains, they are not sure how these were caused. One of the theories is that meteorites hit the rings and create a cloud of charged plasma, which then charges up the rings' dust particles.
Jones says this cannot be the case as the spokes build up gradually and several meteorites cannot be expected to strike the rings at the same time and at the same place. He says thunderstorms could be the case as thunderstorms on Earth are found to generate electron beams. Saturn is known to experience thunderstorms.
The details of the possibilities propounded by Jones and his team appear in the journal Geophysical Research.
