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                        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 May 3
    [2]See Explanation. Clicking on the picture will download the highest
                        resolution version available.

                            A Message from Earth
    Image Credit: [3]Frank Drake ([4]UCSC) et al., [5]Arecibo Observatory
                              ([6]Cornell U.);
                  [7]License: [8]Arne Nordmann (Wikimedia)

   Explanation: What are these Earthlings trying to tell us? The featured
   message was broadcast from [9]Earth towards the [10]globular star
   cluster [11]M13 in 1974. During the dedication of the [12]Arecibo
   Observatory - still one of the largest single radio telescopes in the
   world - a string of 1's and 0's representing the diagram was sent.
   [13]This attempt at extraterrestrial communication was mostly
   ceremonial - [14]humanity regularly broadcasts radio and television
   signals out into space accidentally. Even were [15]this message
   received, M13 is so far away we would [16]have to wait almost 50,000
   years to hear an answer. The [17]featured message gives a few simple
   facts about humanity and its knowledge: from left to right are numbers
   from one to ten, atoms including [18]hydrogen and [19]carbon, some
   interesting molecules, [20]DNA, a human with description, basics of our
   [21]Solar System, and basics of the sending telescope. Several
   [22]searches for extraterrestrial intelligence are currently underway,
   including one where you can [23]use your own home computer.

        Experts Debate: [24]How will humanity first discover ET life?
                      Tomorrow's picture: passing earth
     __________________________________________________________________

      [25]< | [26]Archive | [27]Submissions | [28]Index | [29]Search |
   [30]Calendar | [31]RSS | [32]Education | [33]About APOD | [34]Discuss |
                                    [35]>
     __________________________________________________________________

    Authors & editors: [36]Robert Nemiroff ([37]MTU) & [38]Jerry Bonnell
                                 ([39]UMCP)
          NASA Official: Phillip Newman [40]Specific rights apply.
              [41]NASA Web Privacy Policy and Important Notices
                A service of: [42]ASD at [43]NASA / [44]GSFC
                           & [45]Michigan Tech. U.

References

   1. https://apod.nasa.gov/apod/archivepix.html
   2. https://apod.nasa.gov/apod/image/2005/Message_Arecibo_2000.jpg
   3. https://en.wikipedia.org/wiki/Frank_Drake
   4. https://www.astro.ucsc.edu/
   5. https://www.naic.edu/ao/
   6. https://astro.cornell.edu/
   7. https://creativecommons.org/licenses/by-sa/3.0/deed.en
   8. https://commons.wikimedia.org/wiki/File:Arecibo_message.svg
   9. https://apod.nasa.gov/apod/ap100713.html
  10. http://asterisk.apod.com/viewtopic.php?f=24&t=18009
  11. https://apod.nasa.gov/apod/ap100527.html
  12. https://apod.nasa.gov/apod/ap981129.html
  13. https://en.wikipedia.org/wiki/Arecibo_message
  14. https://apod.nasa.gov/apod/ap190818.html
  15. http://www.youtube.com/watch?v=6qQRQyEodsE
  16. https://i.pinimg.com/originals/e8/c6/86/e8c686cf79b830a7663432989d423ace.jpg
  17. https://www.seti.org/seti-institute/project/details/arecibo-message
  18. https://periodic.lanl.gov/1.shtml
  19. https://periodic.lanl.gov/6.shtml
  20. https://apod.nasa.gov/apod/ap120821.html
  21. https://solarsystem.nasa.gov/solar-system/our-solar-system/overview/
  22. https://en.wikipedia.org/wiki/Search_for_extraterrestrial_intelligence#Ongoing_radio_searches
  23. https://setiathome.berkeley.edu/
  24. https://apod.nasa.gov/debate/debate100th.html
  25. https://apod.nasa.gov/apod/ap200502.html
  26. https://apod.nasa.gov/apod/archivepix.html
  27. https://apod.nasa.gov/apod/lib/apsubmit2015.html
  28. https://apod.nasa.gov/apod/lib/aptree.html
  29. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search
  30. https://apod.nasa.gov/apod/calendar/allyears.html
  31. https://apod.nasa.gov/apod.rss
  32. https://apod.nasa.gov/apod/lib/edlinks.html
  33. https://apod.nasa.gov/apod/lib/about_apod.html
  34. http://asterisk.apod.com/discuss_apod.php?date=200503
  35. https://apod.nasa.gov/apod/ap200504.html
  36. http://www.phy.mtu.edu/faculty/Nemiroff.html
  37. http://www.phy.mtu.edu/
  38. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html
  39. http://www.astro.umd.edu/
  40. https://apod.nasa.gov/apod/lib/about_apod.html#srapply
  41. https://www.nasa.gov/about/highlights/HP_Privacy.html
  42. https://astrophysics.gsfc.nasa.gov/
  43. https://www.nasa.gov/
  44. https://www.nasa.gov/centers/goddard/
  45. http://www.mtu.edu/