                        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 April 29
   The planet Saturn is shown many times down the composite image. The top
   image was taken in 2020 and shows Saturn's rings very clearly, whereas
   the bottom image was taken in 2025 and the rings are only visible as a
    dark line across the planet. The six images show the progression year
     by year. Please see the explanation for more detailed information.

                     Saturn's Rings Appear to Disappear
                   Image Credit & Copyright: Natan Fontes

   Explanation: Where are Saturn's ears? Galileo is credited, in 1610, as
   the first person to see Saturn's rings. Testing out Lipperhey's
   recently co-invented telescope, Galileo did not know what they were and
   so called them "ears". The mystery deepened in 1612, when Saturn's ears
   mysteriously disappeared. Today we know exactly what happened: from the
   perspective of the Earth, Saturn's rings had become too thin to see.
   The same drama plays out every 15 years because Saturn, like Earth,
   undergoes tilt-driven seasons. This means that as Saturn goes around
   the Sun, its equator and rings can tilt noticeably toward the Sun and
   inner Solar System, making them easily visible, but from other orbital
   locations will appear almost not at all. The featured picture from
   Brasilia, Brazil shows a modern version of this sequence: the top
   ring-dominated image was taken in 2020, while the bottom ring-obscure
   image taken earlier in 2025.

             Make Saturn's Rings Musical: Play them like a harp!
                       Tomorrow's picture: smiling sky
     __________________________________________________________________

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

