¿

                        Astronomy Picture of the Day

   [1]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
   [2]Rainbow airglow over the Azores. See Explanation. Moving the cursor
     over the image will bring up an annotated version. Clicking on the
        image will bring up the highest resolution version available.

                        A Meteor and the Gegenschein
      Image Credit: [3]J.C. Casado, [4]StarryEarth, [5]EELabs, [6]TWAN

   Explanation: Is the night sky darkest in the direction opposite the
   Sun? No. In fact, a rarely discernable faint glow known as [7]the
   gegenschein (German for "counter glow") can be seen 180 degrees around
   from the Sun in an extremely [8]dark sky. The gegenschein is sunlight
   back-scattered off small interplanetary [9]dust particles. These dust
   particles are millimeter sized splinters from [10]asteroids and orbit
   in the [11]ecliptic plane of the planets. [12]Pictured here from last
   March is one of the more spectacular pictures of [13]the gegenschein
   yet taken. The deep exposure of an extremely dark sky over [14]Teide
   Observatory in [15]Spain's [16]Canary Islands shows [17]the gegenschein
   as part of extended [18]zodiacal light. Notable background objects
   include a [19]bright meteor (on the left), the [20]Big Dipper (top
   right), and [21]Polaris (far right). The meteor nearly points
   [22]toward Mount Teide, Spain's highest mountain, while the [23]Pyramid
   solar laboratory is visible on the right. During the day, a phenomenon
   like [24]the gegenschein called [25]the glory can be seen in reflecting
   air or clouds opposite the [26]Sun from an airplane.

                       Tomorrow's picture: open space
     __________________________________________________________________

      [27]< | [28]Archive | [29]Submissions | [30]Index | [31]Search |
   [32]Calendar | [33]RSS | [34]Education | [35]About APOD | [36]Discuss |
                                    [37]>
     __________________________________________________________________

    Authors & editors: [38]Robert Nemiroff ([39]MTU) & [40]Jerry Bonnell
                                 ([41]UMCP)
          NASA Official: Phillip Newman [42]Specific rights apply.
              [43]NASA Web Privacy Policy and Important Notices
                A service of: [44]ASD at [45]NASA / [46]GSFC
                           & [47]Michigan Tech. U.

References

   1. https://apod.nasa.gov/apod/archivepix.html
   2. https://apod.nasa.gov/apod/image/2105/GegenscheinBolide_Casado_2500.jpg
   3. http://twanight.org/profile/juan-carlos-casado/
   4. https://www.flickr.com/photos/starryearth/albums/
   5. https://www.eelabs.eu/
   6. https://twanight.org/about/
   7. http://en.wikipedia.org/wiki/Gegenschein
   8. https://www.darksky.org/
   9. https://apod.nasa.gov/apod/ap010813.html
  10. https://apod.nasa.gov/apod/ap980712.html
  11. https://apod.nasa.gov/apod/ap151126.html
  12. https://www.instagram.com/p/COfkiYNpzdP/
  13. http://www.as.wvu.edu/~jel/skywatch/skw9810h.html
  14. https://en.wikipedia.org/wiki/Teide_Observatory
  15. https://en.wikipedia.org/wiki/Spain
  16. https://en.wikipedia.org/wiki/Canary_Islands
  17. http://io9.com/5662511/gegenschein-the-glowing-circle-in-the-sky
  18. https://apod.nasa.gov/apod/ap210311.html
  19. https://solarsystem.nasa.gov/asteroids-comets-and-meteors/meteors-and-meteorites/overview/
  20. https://www.adlerplanetarium.org/blog/discover-big-dipper/
  21. https://starchild.gsfc.nasa.gov/docs/StarChild/questions/question64.html
  22. https://youtu.be/Vx0jimhalAU
  23. https://3dwarehouse.sketchup.com/model/a25ba51c87e33afc465ebc912c8fdaee/Laboratorio-Solar
  24. https://ui.adsabs.harvard.edu/abs/1997MNRAS.288.1022J/abstract
  25. https://apod.nasa.gov/apod/ap161222.html
  26. https://solarsystem.nasa.gov/solar-system/sun/overview/
  27. https://apod.nasa.gov/apod/ap210511.html
  28. https://apod.nasa.gov/apod/archivepix.html
  29. https://apod.nasa.gov/apod/lib/apsubmit2015.html
  30. https://apod.nasa.gov/apod/lib/aptree.html
  31. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search
  32. https://apod.nasa.gov/apod/calendar/allyears.html
  33. https://apod.nasa.gov/apod.rss
  34. https://apod.nasa.gov/apod/lib/edlinks.html
  35. https://apod.nasa.gov/apod/lib/about_apod.html
  36. http://asterisk.apod.com/discuss_apod.php?date=210512
  37. https://apod.nasa.gov/apod/ap210513.html
  38. http://www.phy.mtu.edu/faculty/Nemiroff.html
  39. http://www.phy.mtu.edu/
  40. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html
  41. http://www.astro.umd.edu/
  42. https://apod.nasa.gov/apod/lib/about_apod.html#srapply
  43. https://www.nasa.gov/about/highlights/HP_Privacy.html
  44. https://astrophysics.gsfc.nasa.gov/
  45. https://www.nasa.gov/
  46. https://www.nasa.gov/centers/goddard/
  47. http://www.mtu.edu/