Earth isn’t the only planet
in the solar system with spectacular light shows. Both Jupiter and Saturn have
magnetic fields much stronger than Earth’s. Auroras also have been observed on
the surfaces of Venus, Mars and even on moons (e.g. Io, Europa, and Ganymede).
The auroras on Saturn are created when solar wind particles are channeled into
the planet’s magnetic field toward its poles, where they interact with
electrically charged gas (plasma) in the upper atmosphere and emit light.
Aurora features on Saturn
can also be caused by electromagnetic waves generated when its moons move
through the plasma that fills the planet’s magnetosphere. The main source
is the small moon Enceladus, which ejects water vapor from the geysers on its
south pole, a portion of which is ionized. The interaction between Saturn’s
magnetosphere and the solar wind generates bright oval aurora around the
planet’s poles observed in visible, infrared and ultraviolet light.
The aurora of Saturn are
highly variable. Their location and brightness strongly depends on the Solar
wind pressure: the aurora become brighter and move closer to the poles when the
Solar wind pressure increases.
Credit: ESA/Hubble (M. K)
Credit: ESA/Hubble (M. K)
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