                        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.

                                2025 April 13
    A brown background is shown covered with a gray topping that has many
        holes. On the upper right, there is a deep hole in the brown
        background. In this hole is more gray topping. Please see the
                 explanation for more detailed information.

                           An Unusual Hole in Mars
              Image Credit: NASA, MRO, HiRISE, JPL, U. Arizona

   Explanation: What created this unusual hole in Mars? Actually, there
   are numerous holes pictured in this Swiss cheese-like landscape, with
   all-but-one of them showing a dusty, dark, Martian terrain beneath
   evaporating, light, carbon dioxide ice. The most unusual hole is on the
   upper right, spans about 100 meters, and seems to punch through to a
   lower level. Why this hole exists and why it is surrounded by a
   circular crater remains a topic of speculation, although a leading
   hypothesis is that it was created by a meteor impact. Holes such as
   this are of particular interest because they might be portals to lower
   levels that extend into expansive underground caves. If so, these
   naturally occurring tunnels are relatively protected from the harsh
   surface of Mars, making them relatively good candidates to contain
   Martian life. These pits are therefore also prime targets for possible
   future spacecraft, robots, and even human interplanetary explorers.

                      Tomorrow's picture: radio center
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       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
            NASA Official: Amber Straughn Specific rights apply.
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                      A service of: ASD at NASA / GSFC,
                           NASA Science Activation
                             & Michigan Tech. U.

