                        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 December 19

                     Long Shadows of the Montes Caucasus
                    Image Credit & Copyright: Guy Bardon

   Explanation: When the Moon is at its first quarter phase, the Sun rises
   along the Montes Caucasus as seen from the lunar surface. The lunar
   mountain range casts the magnificent, spire-like shadows in this
   telescopic view from planet Earth, looking along the lunar terminator
   or the boundary between lunar night and day. Named for Earth's own
   Caucasus Mountains, the rugged lunar Montes Caucasus peaks, up to 6
   kilometers high, are located between the smooth Mare Imbrium to the
   west and Mare Serenitatis to the east. Still mostly in shadow in this
   first quarter lunarscape, at the left (west) impact craters reflect the
   light of the rising Sun along their outer, eastern crater walls.

                    Tomorrow's picture: the Sun's tattoo
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       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
            NASA Official: Amber Straughn Specific rights apply.
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