                        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.

                               2024 December 8
        A picture of Saturn is shown with tan clouds and light rings.
    Surrounding the north pole at the top are bright blue swirls. Please
             see the explanation for more detailed information.

                      Aurora around Saturn's North Pole
    Image Credit: NASA, ESA, Hubble, OPAL Program, J. DePasquale (STScI),
                            L. Lamy (Obs. Paris)

   Explanation: Are Saturn's auroras like Earth's? To help answer this
   question, the Hubble Space Telescope and the Cassini spacecraft
   monitored Saturn's North Pole simultaneously during Cassini's final
   orbits around the gas giant in September 2017. During this time,
   Saturn's tilt caused its North Pole to be clearly visible from Earth.
   The featured image is a composite of ultraviolet images of auroras and
   optical images of Saturn's clouds and rings, all taken by Hubble. Like
   on Earth, Saturn's northern auroras can make total or partial rings
   around the pole. Unlike on Earth, however, Saturn's auroras are
   frequently spirals -- and more likely to peak in brightness just before
   midnight and dawn. In contrast to Jupiter's auroras, Saturn's auroras
   appear better related to connecting Saturn's internal magnetic field to
   the nearby, variable, solar wind. Saturn's southern auroras were
   similarly imaged back in 2004 when the planet's South Pole was clearly
   visible to Earth.

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                                 (post 1995)
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       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
            NASA Official: Amber Straughn Specific rights apply.
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                      A service of: ASD at NASA / GSFC,
                           NASA Science Activation
                             & Michigan Tech. U.

