                        Astronomy Picture of the Day

    Discover the cosmos! Each day a different image or photograph of our
      fascinating universe is featured, along with a brief explanation
                    written by a professional astronomer.

                                2021 June 27

                        The Dancing Auroras of Saturn
   Image Credit: NASA, Cassini, VIMS Team, U. Arizona, U. Leicester, JPL,
                                     ASI

   Explanation: What drives auroras on Saturn? To help find out,
   scientists have sorted through hundreds of infrared images of Saturn
   taken by the Cassini spacecraft for other purposes, trying to find
   enough aurora images to correlate changes and make movies. Once made,
   some movies clearly show that Saturnian auroras can change not only
   with the angle of the Sun, but also as the planet rotates. Furthermore,
   some auroral changes appear related to waves in Saturn's magnetosphere
   likely caused by Saturn's moons. Pictured here, a false-colored image
   taken in 2007 shows Saturn in three bands of infrared light. The rings
   reflect relatively blue sunlight, while the planet itself glows in
   comparatively low energy red. A band of southern aurora in visible in
   green. In has recently been found that auroras heat Saturn's upper
   atmosphere. Understanding Saturn's auroras is a path toward a better
   understanding of Earth's auroras.

                   Tomorrow's picture: paper moon eclipse
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       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
            NASA Official: Phillip Newman Specific rights apply.
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                             & Michigan Tech. U.

