                        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 May 12

                        A Meteor and the Gegenschein
            Image Credit: J.C. Casado, StarryEarth, EELabs, TWAN

   Explanation: Is the night sky darkest in the direction opposite the
   Sun? No. In fact, a rarely discernable faint glow known as the
   gegenschein (German for "counter glow") can be seen 180 degrees around
   from the Sun in an extremely dark sky. The gegenschein is sunlight
   back-scattered off small interplanetary dust particles. These dust
   particles are millimeter sized splinters from asteroids and orbit in
   the ecliptic plane of the planets. Pictured here from last March is one
   of the more spectacular pictures of the gegenschein yet taken. The deep
   exposure of an extremely dark sky over Teide Observatory in Spain's
   Canary Islands shows the gegenschein as part of extended zodiacal
   light. Notable background objects include a bright meteor (on the
   left), the Big Dipper (top right), and Polaris (far right). The meteor
   nearly points toward Mount Teide, Spain's highest mountain, while the
   Pyramid solar laboratory is visible on the right. During the day, a
   phenomenon like the gegenschein called the glory can be seen in
   reflecting air or clouds opposite the Sun from an airplane.

                       Tomorrow's picture: open space
     __________________________________________________________________

       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
            NASA Official: Phillip Newman Specific rights apply.
                NASA Web Privacy Policy and Important Notices
                      A service of: ASD at NASA / GSFC
                             & Michigan Tech. U.

