                        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.

                                2023 July 23
    An old and corroded mechanism is shown fronted by a large wheel. The
    mechanism has patches of tan and brown color but it is mostly green.
          Please see the explanation for more detailed information.

                          The Antikythera Mechanism
                 Image Credit & License: Marsyas, Wikipedia

   Explanation: It does what? No one knew that 2,000 years ago, the
   technology existed to build such a device. The Antikythera mechanism,
   pictured, is now widely regarded as the first computer. Found at the
   bottom of the sea aboard a decaying Greek ship, its complexity prompted
   decades of study, and even today some of its functions likely remain
   unknown. X-ray images of the device, however, have confirmed that a
   main function of its numerous clock-like wheels and gears is to create
   a portable, hand-cranked, Earth-centered, orrery of the sky, predicting
   future star and planet locations as well as lunar and solar eclipses.
   The corroded core of the Antikythera mechanism's largest gear is
   featured, spanning about 13 centimeters, while the entire mechanism was
   33 centimeters high, making it similar in size to a large book.
   Recently, modern computer modeling of missing components is allowing
   for the creation of a more complete replica of this surprising ancient
   machine.

                     Tomorrow's picture: rainbow meteor
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       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
            NASA Official: Phillip Newman Specific rights apply.
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                           NASA Science Activation
                             & Michigan Tech. U.
