                        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 June 28

                                Lunar Farside
   Image Credit: NASA / GSFC / Arizona State Univ. / Lunar Reconnaissance
                                   Orbiter

   Explanation: Tidally locked in synchronous rotation, the Moon always
   presents its familiar nearside to denizens of planet Earth. From lunar
   orbit, the Moon's farside can become familiar, though. In fact this
   sharp picture, a mosaic from the Lunar Reconnaissance Orbiter's wide
   angle camera, is centered on the lunar farside. Part of a global mosaic
   of over 15,000 images acquired between November 2009 and February 2011,
   the highest resolution version shows features at a scale of 100 meters
   per pixel. Surprisingly, the rough and battered surface of the farside
   looks very different from the nearside covered with smooth dark lunar
   maria. A likely explanation is that the farside crust is thicker,
   making it harder for molten material from the interior to flow to the
   surface and form dark, smooth maria.

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

