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.

                                 2020 July 4
    [2]See Explanation. Clicking on the picture will download the highest
                        resolution version available.

                          Meeting in the Mesosphere
     Image Credit & [3]Copyright: [4]Stephane Vetter ([5]TWAN, [6]Nuits
                                  sacrees)

   Explanation: A sensitive video camera on a summit of the Vosges
   mountains in France captured these surprising fireworks above a
   [7]distant horizon on June 26. [8]Generated over intense thunderstorms,
   this one about 260 kilometers away, the brief and mysterious flashes
   have come to be known as red sprites. The transient luminous events are
   caused by electrical breakdown at altitudes of 50 to 100 kilometers.
   [9]That puts them in the mesophere, the coldest layer of planet Earth's
   atmosphere. The glow beneath the sprites is from more familiar lighting
   though, below the storm clouds. But on the right, the video frames have
   captured another summertime apparition from the mesophere. [10]The
   silvery veins of light are polar mesospheric clouds. Also known as
   noctilucent or night shining clouds, the icy clouds still [11]reflect
   the sunlight when the Sun is below the horizon.

                    Tomorrow's picture: Saturn six-sided
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    Authors & editors: [23]Robert Nemiroff ([24]MTU) & [25]Jerry Bonnell
                                 ([26]UMCP)
          NASA Official: Phillip Newman [27]Specific rights apply.
              [28]NASA Web Privacy Policy and Important Notices
                A service of: [29]ASD at [30]NASA / [31]GSFC
                           & [32]Michigan Tech. U.

References

   1. https://apod.nasa.gov/apod/archivepix.html
   2. https://apod.nasa.gov/apod/image/2007/msv1500crop.jpg
   3. https://apod.nasa.gov/apod/lib/about_apod.html#srapply
   4. https://www.facebook.com/stephane.vetter.nuitsacrees
   5. http://www.twanight.org/newTWAN/index.asp
   6. http://www.nuitsacrees.fr/
   7. http://nuitsacrees.fr/DP/AP61/map2020-06-26_2135.jpg
   8. https://www.nasa.gov/mission_pages/station/research/Once_Upon_a_Time_in_a_Thunderstorm
   9. https://www.aeronomie.be/en/encyclopedia/mesosphere-coldest-layer-earths-atmosphere
  10. https://apod.nasa.gov/apod/ap200619.html
  11. https://www.loc.gov/item/ihas.200000017
  12. https://apod.nasa.gov/apod/ap200703.html
  13. https://apod.nasa.gov/apod/archivepix.html
  14. https://apod.nasa.gov/apod/lib/apsubmit2015.html
  15. https://apod.nasa.gov/apod/lib/aptree.html
  16. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search
  17. https://apod.nasa.gov/apod/calendar/allyears.html
  18. https://apod.nasa.gov/apod.rss
  19. https://apod.nasa.gov/apod/lib/edlinks.html
  20. https://apod.nasa.gov/apod/lib/about_apod.html
  21. http://asterisk.apod.com/discuss_apod.php?date=200704
  22. https://apod.nasa.gov/apod/ap200705.html
  23. http://www.phy.mtu.edu/faculty/Nemiroff.html
  24. http://www.phy.mtu.edu/
  25. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html
  26. http://www.astro.umd.edu/
  27. https://apod.nasa.gov/apod/lib/about_apod.html#srapply
  28. https://www.nasa.gov/about/highlights/HP_Privacy.html
  29. https://astrophysics.gsfc.nasa.gov/
  30. https://www.nasa.gov/
  31. https://www.nasa.gov/centers/goddard/
  32. http://www.mtu.edu/