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.

                                 2020 May 3

                            A Message from Earth
    Image Credit: Frank Drake (UCSC) et al., Arecibo Observatory (Cornell
                                    U.);
                     License: Arne Nordmann (Wikimedia)

   Explanation: What are these Earthlings trying to tell us? The featured
   message was broadcast from Earth towards the globular star cluster M13
   in 1974. During the dedication of the 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. This attempt at
   extraterrestrial communication was mostly ceremonial - humanity
   regularly broadcasts radio and television signals out into space
   accidentally. Even were this message received, M13 is so far away we
   would have to wait almost 50,000 years to hear an answer. The featured
   message gives a few simple facts about humanity and its knowledge: from
   left to right are numbers from one to ten, atoms including hydrogen and
   carbon, some interesting molecules, DNA, a human with description,
   basics of our Solar System, and basics of the sending telescope.
   Several searches for extraterrestrial intelligence are currently
   underway, including one where you can use your own home computer.

          Experts Debate: How will humanity first discover ET life?
                      Tomorrow's picture: passing earth
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       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
            NASA Official: Phillip Newman Specific rights apply.
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                      A service of: ASD at NASA / GSFC
                             & Michigan Tech. U.

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