                 APOD: 2018 January 25 - Cartwheel of Fortune

                         Astronomy Picture of the Day

    Discover the cosmos! [1] Each day a different image or photograph of our
 fascinating universe is featured, along with a brief explanation written by a
                           professional astronomer.

                                2018 January 25
                                      [2]
                            Cartwheel of Fortune
                       Image Credit: ESA [3] , NASA [4]

Explanation: By chance, a collision of two galaxies has created a surprisingly
recognizable shape on a cosmic scale, The Cartwheel Galaxy [5] . The Cartwheel
is part of a group of galaxies about 500 million light years away in the
constellation Sculptor. Two smaller galaxies in the group are visible on the
right. The Cartwheel Galaxy's rim is an immense ring-like structure [6]
150,000 light years in diameter composed of newly formed, extremely bright,
massive stars. When galaxies collide [7]  they pass through each other, their
individual stars rarely coming into contact. Still, the galaxies'
gravitational fields are seriously distorted by the collision. In fact, the
ring-like shape is the result of the gravitational disruption caused by a
small intruder galaxy passing through a large one, compressing the
interstellar gas and dust and causing a a star formation wave to move out from
the impact point like a ripple across the surface of a pond. In this case the
large galaxy may have originally been a spiral, not unlike our own Milky Way
[8] , transformed into the wheel shape by the collision. But ... what happened
to the small intruder galaxy [9] ?

                      Tomorrow's picture: sol 1943 [10]

-------------------------------------------------------------------------------
< [11] | Archive [12] | Submissions [13] | Index [14] | Search [15] | Calendar
  [16] | RSS [17] | Education [18] | About APOD [19] | Discuss [20] | > [21]
-------------------------------------------------------------------------------

    Authors & editors: Robert Nemiroff [22] (MTU [23] ) & Jerry Bonnell [24]
                                  (UMCP [25] )
          NASA Official:  Phillip Newman Specific rights apply [26] .
              NASA Web Privacy Policy and Important Notices [27]
              A service of: ASD [28]  at NASA [29]  / GSFC [30]
                           & Michigan Tech. U. [31]
----------
Site notes:
  [1] archivepix.html
  [2] image/1801/cartwheel_hst.jpg
  [3] http://spacetelescope.org/images/potw1036a/
  [4] https://www.nasa.gov/
  [5] http://spacetelescope.org/images/potw1036a/
  [6] http://chandra.harvard.edu/photo/2006/cartwheel/
  [7] http://burro.cwru.edu/JavaLab/GalCrashWeb/
  [8] ap080606.html
  [9] ap970224.html
  [10] ap180126.html
  [11] ap180124.html
  [12] archivepix.html
  [13] lib/apsubmit2015.html
  [14] lib/aptree.html
  [15] https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search
  [16] calendar/allyears.html
  [17] /apod.rss
  [18] lib/edlinks.html
  [19] lib/about_apod.html
  [20] http://asterisk.apod.com/discuss_apod.php?date=180125
  [21] ap180126.html
  [22] http://www.phy.mtu.edu/faculty/Nemiroff.html
  [23] http://www.phy.mtu.edu/
  [24] https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html
  [25] http://www.astro.umd.edu/
  [26] lib/about_apod.html#srapply
  [27] https://www.nasa.gov/about/highlights/HP_Privacy.html
  [28] https://astrophysics.gsfc.nasa.gov/
  [29] https://www.nasa.gov/
  [30] https://www.nasa.gov/centers/goddard/
  [31] http://www.mtu.edu/
