Auroral Arrhythmia

Saturn's north and south auroras seen by Hubble

Just like Earth, Saturn has its own versions of northern (and southern) lights illuminating high-altitude rings around its polar latitudes. Understandably much larger and more powerful than our planet’s auroras, they are nevertheless caused by the same thing: energetic particles streaming out from the sun get caught in Saturn’s magnetic field and are funneled toward the planet’s poles where they get crowded together, whack into atoms in the upper layers of the atmosphere and emit energy in the form of visible light. The Hubble Space Telescope was able to catch a glimpse of Saturn’s auroras in 2009, and the Cassini spacecraft even made a video of the northern lights in action.

Last week a European team released interesting news that Saturn’s auroras seem to pulse to the rhythm of a “mysterious radio emission” known as the Saturn Kilometric Radiation (SKR), which emanates from the planet’s poles. Once believed to keep pace with Saturn’s rotation, it’s now looking like the SKR’s – and auroras’ – rate varies over time independently of the rotation, which operates at a constant rate.

“This is an important discovery for two reasons. First, it provides a long-suspected but hitherto missing link between the radio and auroral emissions, and second, it adds a critical tool in diagnosing the cause of Saturn’s irregular heartbeat.”

– Dr. Jonathan Nichols, University of Leicester

Read more on the ESA’s Hubble site here.

Image credit: NASA, ESA and Jonathan Nichols (University of Leicester)

3 Comments

  1. Lauri says:

    I had no idea Saturn had auroras! Fascinating!

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    1. J. Major says:

      I suppose any planet with a magnetic field and an atmosphere can have auroras….I would guess!

      Mercury has a strong magnetic field but no real atmosphere, so it has a “plasma nebula” of particles caught in its donut-shaped magnetosphere. (http://science.nasa.gov/science-news/science-at-nasa/2008/01oct_mercuryflyby2/)

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