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 24

                 Valles Marineris: The Grand Canyon of Mars
                  Image Credit: NASA, USGS, Viking Project

   Explanation: The largest canyon in the Solar System cuts a wide swath
   across the face of Mars. Named Valles Marineris, the grand valley
   extends over 3,000 kilometers long, spans as much as 600 kilometers
   across, and delves as much as 8 kilometers deep. By comparison, the
   Earth's Grand Canyon in Arizona, USA is 800 kilometers long, 30
   kilometers across, and 1.8 kilometers deep. The origin of the Valles
   Marineris remains unknown, although a leading hypothesis holds that it
   started as a crack billions of years ago as the planet cooled. Several
   geologic processes have been identified in the canyon. The featured
   mosaic was created from over 100 images of Mars taken by Viking
   Orbiters in the 1970s.

                  Tomorrow's picture: interstellar monster
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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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