                        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.

                               2024 August 21
     A blue oval is shown with a red and yellow horizontal band running
   across the middle. Red and yellow spots also appear distributed inside
     the oval. Please see the explanation for more detailed information.

                    Fermi's 12-year All-Sky Gamma-ray Map
    Image Credit: NASA, DOE, Fermi LAT Collaboration; Text: Barb Mattson
                         (U. Maryland, NASA's GSFC)

   Explanation: Forget X-ray vision — imagine what you could see with
   gamma-ray vision! The featured all-sky map shows what the universe
   looks like to NASA's Fermi Gamma-ray Space Telescope. Fermi sees light
   with energies about a billion times what the human eye can see, and the
   map combines 12 years of Fermi observations. The colors represent the
   brightness of the gamma-ray sources, with brighter sources appearing
   lighter in color. The prominent stripe across the middle is the central
   plane of our Milky Way galaxy. Most of the red and yellow dots
   scattered above and below the Milky Way’s plane are very distant
   galaxies, while most of those within the plane are nearby pulsars. The
   blue background that fills the image is the diffuse glow of gamma-rays
   from distant sources that are too dim to be detected individually. Some
   gamma-ray sources remain unidentified and topics of research —
   currently no one knows what they are.

                       Tomorrow's picture: open space
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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.

