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 December 20
      [2]The featured image shows Comet Leonard in the backround with a
     bright green fireball meteor in the foreground. The image was taken
     from northern California, USA. Please see the explanation for more
                            detailed information.

                         The Comet and the Fireball
                   Image Credit & Copyright: [3]Cory Poole

   Explanation: This picture was supposed to feature a comet.
   Specifically, a series of images of the [4]brightest comet of 2021 were
   being captured: [5]Comet Leonard. But [6]the universe had other plans.
   Within a fraction of a second, a [7]meteor so bright it could be called
   a fireball [8]streaked through just below the comet. And the
   [9]meteor's flash was even more green than the comet's coma. The cause
   of the [10]meteor's green was likely [11]magnesium evaporating from the
   meteor's pebble-sized core, while the cause of the [12]comet's green
   was likely [13]diatomic carbon recently ejected from the comet's
   [14]city-sized nucleus. The images were taken 10 days ago over the
   [15]Sacramento River and [16]Mt. Lassen in [17]California, [18]USA. The
   fireball was on the leading edge of this year's [19]Geminid Meteor
   Shower -- which peaked a few days later. [20]Comet Leonard is now
   fading after reaching naked-eye visibility last week -- but now is
   [21]moving into southern skies.

                Almost Hyperspace: [22]Random APOD Generator
                    Tomorrow's picture: a solar milky way
     __________________________________________________________________

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    Authors & editors: [34]Robert Nemiroff ([35]MTU) & [36]Jerry Bonnell
                                 ([37]UMCP)
          NASA Official: Phillip Newman [38]Specific rights apply.
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                A service of: [40]ASD at [41]NASA / [42]GSFC
                           & [43]Michigan Tech. U.

References

   1. https://apod.nasa.gov/apod/archivepix.html
   2. https://apod.nasa.gov/apod/image/2112/LeonardMeteor_Poole_2250.jpg
   3. mailto:%20corypoole%20@at@%20gmail%20.dot.%20com
   4. https://www.facebook.com/media/set/?set=a.4214632848640902&type=3
   5. https://en.wikipedia.org/wiki/C/2021_A1_(Leonard)
   6. https://apod.nasa.gov/apod/ap000101.html
   7. https://solarsystem.nasa.gov/asteroids-comets-and-meteors/meteors-and-meteorites/overview/
   8. https://i1.wp.com/theverybesttop10.com/wp-content/uploads/2014/01/Top-10-Best-Images-of-Surprised-Cats-4.jpeg
   9. https://apod.nasa.gov/apod/ap210315.html
  10. https://en.wikipedia.org/wiki/Meteoroid#Colours
  11. https://periodic.lanl.gov/12.shtml
  12. https://www.cloudynights.com/topic/406505-green-in-comets-is-not-cn-cyanogen/
  13. https://en.wikipedia.org/wiki/Diatomic_carbon
  14. https://www.mentalfloss.com/article/60082/rosettas-comet-compared-los-angeles
  15. https://youtu.be/CDgOFPuDRlU
  16. https://youtu.be/ttbxcarLYQQ?t=20
  17. https://en.wikipedia.org/wiki/California
  18. https://en.wikipedia.org/wiki/United_States
  19. https://apod.nasa.gov/apod/ap211216.html
  20. https://theskylive.com/how-bright-is-cometleonard
  21. https://en.wikipedia.org/wiki/C/2021_A1_(Leonard)#/media/File:Animation_of_C%EF%BC%8F2021_A1's_orbit_around_Sun_-_2021_close_approach.gif
  22. https://apod.nasa.gov/apod/random_apod.html
  23. https://apod.nasa.gov/apod/ap211219.html
  24. https://apod.nasa.gov/apod/archivepix.html
  25. https://apod.nasa.gov/apod/lib/apsubmit2015.html
  26. https://apod.nasa.gov/apod/lib/aptree.html
  27. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search
  28. https://apod.nasa.gov/apod/calendar/allyears.html
  29. https://apod.nasa.gov/apod.rss
  30. https://apod.nasa.gov/apod/lib/edlinks.html
  31. https://apod.nasa.gov/apod/lib/about_apod.html
  32. http://asterisk.apod.com/discuss_apod.php?date=211220
  33. https://apod.nasa.gov/apod/ap211221.html
  34. http://www.phy.mtu.edu/faculty/Nemiroff.html
  35. http://www.phy.mtu.edu/
  36. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html
  37. http://www.astro.umd.edu/
  38. https://apod.nasa.gov/apod/lib/about_apod.html#srapply
  39. https://www.nasa.gov/about/highlights/HP_Privacy.html
  40. https://astrophysics.gsfc.nasa.gov/
  41. https://www.nasa.gov/
  42. https://www.nasa.gov/centers/goddard/
  43. http://www.mtu.edu/