                        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.

                              2025 September 14

                Planets of the Solar System: Tilts and Spins
        Video Credit: NASA, Animation: James O'Donoghue (U. Reading)

   Explanation: How does your favorite planet spin? Does it spin rapidly
   around a nearly vertical axis, or horizontally, or backwards? The
   featured video animates NASA images of all eight planets in our Solar
   System to show them spinning side-by-side for an easy comparison. In
   the time-lapse video, a day on Earth -- one Earth rotation -- takes
   just a few seconds. Jupiter rotates the fastest, while Venus spins not
   only the slowest (can you see it?), but backwards. The inner rocky
   planets across the top underwent dramatic spin-altering collisions
   during the early days of the Solar System. Why planets spin and tilt as
   they do remains a topic of research with much insight gained from
   modern computer modeling and the recent discovery and analysis of
   hundreds of exoplanets: planets orbiting other stars.

                        Tomorrow's picture: sun belch
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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.

