2011年4月22日星期五

Aurora of moon of Saturn 'Circuit'

April 21, 2011 last updated at 14: 52 GMT Saturn's northern aurorae (NASA/JPL/University of Colorado/Central Arizona College) Aurora differ widely in intensity and they are generally weaker by the Jupiter-Saturn is a flickering "northern lights" phenomenon thanks to a flow of electrons to and from his Moon of Enceladus, researchers say.

A report in nature suggests this Aurora would be weak, and in the ultraviolet part of the light spectrum.

The electrical "circuit" between Jupiter and three of its moons is similar to search by the Cassini probe.

Electrons flow from Enceladus Poland in a large loop and Aurora result and where they hit Saturn's magnetic field.

The Aurora process is similar to what is happening in high latitudes of the Earth; Here are the paths of the fast-moving charged particles from the solar wind magnetic field of the Earth curved and emit the shows we know as the northern and southern lights.

On the other hand the fields cover created by Jupiter and Saturn moons of, and what is known conclusion what brings is particles directly from the satellite, an electrical circuit as electrodynamic coupling in fact.

The mechanism behind Jupiter's Aurora is believed that its sulphur content of its Moon of IO's volcanic activity, divided by the sunlight into electrons and ions.

On Saturn's moon of Enceladus, however is the suspected source of the electrons "Cryovolcanism" - volcanic activity, the above liquids or at Enceladus, salty ice shoots.

'Rare opportunity' Saturn and its rings last year, the Cassini mission was extended to 2017

The spacecraft Cassini studied Saturn and its moons since it came in 2004 having made 12 close passes of Enceladus.

The close encounter, which on 11 August 2008 occurred on, scientists discovered a large stream of ions (molecules with electrons removed) of Moon and then confirms the electron loops.

"I think it is a very interesting discovery, very exciting," said Andrew Coates, co-author of the paper of the University College London.

"Five or six years, we did not know that Enceladus was material in the solar system - plaster, now we exciting effects, such as the magnetic and electrical current links in the ionosphere of Saturn produced this (Aurora) in place," he told BBC News.

The team says, that the Aurora about one-tenth the intensity of those on Jupiter seen, and that in intensity - by as much as three times vary.

The they of date, is down to the variations in the output of the geysers which are feeding the process - a process, says Professor Coates seems likely to happen somewhere else.

"It is likely a universal process;" It could be something that happens in other places like [Neptune's moon] Triton or extrasolar planets where it 'hot Jupiter'. "


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