                        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 July 26

                A Flight through the Hubble Ultra Deep Field
       Video Credit: NASA, ESA, F. Summers, Z. Levay, L. Frattare, B.
              Mobasher, A. Koekemoer and the HUDF Team (STScI)

   Explanation: What would it look like to fly through the distant
   universe? To find out, a team of astronomers estimated the relative
   distances to over 5,000 galaxies in one of the most distant fields of
   galaxies ever imaged: the Hubble Ultra Deep Field (HUDF). Because it
   takes light a long time to cross the universe, most galaxies visible in
   the featured video are seen when the universe was only a fraction of
   its current age, were still forming, and have unusual shapes when
   compared to modern galaxies. No mature looking spiral galaxies such as
   our Milky Way or the Andromeda galaxy yet exist. Toward the end of the
   video the virtual observer flies past the farthest galaxies in the HUDF
   field, recorded to have a redshift past 8. This early class of low
   luminosity galaxies likely contained energetic stars emitting light
   that transformed much of the remaining normal matter in the universe
   from a cold gas to a hot ionized plasma.

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       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
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