While Jupiter, like Earth, sports auroras above its polar regions, scientists now believe the gas giant may have more than one way to cause the ion-powered light shows.

On Earth and Saturn, Jupiter’s gassy neighbor, auroras are triggered by solar storms of energetic particles, which disturb the magnetic fields around the planets.

But Jupiter's rapid rotation, intense magnetic field, and abundant source of particles from its volcanically active moon Io create a huge reservoir of electrons and ions. As the charged particles become trapped in Jupiter's magnetic field, they are continually accelerated down into the atmosphere above the polar regions, where they collide with gases to produce nearly always active aurora that are typically 1,000 times more powerful than Earth’s, researchers said.

Electric voltages of about 10 million volts, and currents of 10 million amps - a hundred times greater than the most powerful lightning bolts - are required to explain X-ray observations (seen here) of Jupiter’s auroras taken by the orbiting Chandra X-ray Observatory.

The schematic (left) illustrates how Jupiter's unusually frequent and spectacular auroral activity is produced. Jupiter's strong, rapidly rotating magnetic field (light blue lines) generates strong electric fields in the space around the planet. Particles (white dots) from Jupiter's volcanically active moon, Io, drift outward to create a particle reservoir.

Chandra observed Jupiter with its Advanced CCD Imaging Spectrometer in February 2003 for four rotations of the planet (approximately 40 hours) during intense auroral activity.

-- SPACE.com Staff

Credit: NASA/CXC/MSFC/R.Elsner et al.; Illustration: CXC/M.Weiss.

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