Astronomers have known for decades that our Milky Way Galaxy and the neighboring Andromeda Galaxy are approaching each other. What we haven't known is just how close the encounter will be. Recent Hubble measurements have been able to pin down the trajectory with a smashing conclusion: in about four billion years the two galaxies will crash together in a nearly head-on collision. Further, the spiral galaxies will have completely merged and transformed to create a single elliptical galaxy around six billion years in the future.
<p>"Hubble's Universe Unfiltered" is a recurring broadcast from HubbleSite.org, online home of the Hubble Space Telescope. Astrophysicist Frank Summers takes viewers on an in-depth tour of the latest Hubble discoveries. Find more episodes at HubbleSite.org.
</p><p>HubbleSite page: <a rel="nofollow" class="external free" href="http://hubblesite.org/explore_astronomy/hubbles_universe_unfiltered/episodes/17">http://hubblesite.org/explore_astronomy/hubbles_universe_unfiltered/episodes/17</a>
</p>
<ul><li>Notes</li></ul><p>NASA's Hubble Shows Milky Way is Destined for Head-on Collision with Andromeda Galaxy:
<a rel="nofollow" class="external free" href="http://hubblesite.org/newscenter/archive/releases/2012/20/">http://hubblesite.org/newscenter/archive/releases/2012/20/</a>
</p><p>Milky Way drawing
Credit: NASA, JPL-Caltech, R. Hurt (SSC-Caltech)
<a rel="nofollow" class="external free" href="http://www.spitzer.caltech.edu/images/1923-ssc2008-10a-A-Roadmap-to-the-Milky-Way">http://www.spitzer.caltech.edu/images/1923-ssc2008-10a-A-Roadmap-to-the-Milky-Way</a>
</p><p>Milky Way panorama
Copyright: Axel Mellinger (used with permission)
<a rel="nofollow" class="external free" href="http://home.arcor-online.de/axel.mellinger/">http://home.arcor-online.de/axel.mellinger/</a>
</p><p>Large Magellanic Cloud
Credit: David Malin
Copyright: Australian Astronomical Observatory (used with permission)
<a rel="nofollow" class="external free" href="http://www.aao.gov.au/images/captions/uks014.html">http://www.aao.gov.au/images/captions/uks014.html</a>
</p><p>Small Magellanic Cloud
Credit: NOAO/AURA/NSF
<a rel="nofollow" class="external free" href="http://www.noao.edu/image_gallery/html/im0563.html">http://www.noao.edu/image_gallery/html/im0563.html</a>
</p><p>Andromeda Galaxy
Credit: Bill Schoening, Vanessa Harvey/REU program/NOAO/AURA/NSF
<a rel="nofollow" class="external free" href="http://www.noao.edu/image_gallery/html/im0424.html">http://www.noao.edu/image_gallery/html/im0424.html</a>
</p><p>Triangulum Galaxy
Credit: T.A.Rector (NRAO/AUI/NSF and NOAO/AURA/NSF) and M.Hanna (NOAO/AURA/NSF)
<a rel="nofollow" class="external free" href="http://www.noao.edu/image_gallery/html/im0775.html">http://www.noao.edu/image_gallery/html/im0775.html</a>
</p><p>Local Group Schematic
Credit: Christine Godfrey
</p><p>Visible Light Spectrum
Credit: Wikimedia Commons user Philip Roman
<a href="//commons.wikimedia.org/wiki/File:EM_spectrum.svg" title="File:EM spectrum.svg">File:EM_spectrum.svg</a>
</p><p>Neon Pizza Sign
<a rel="nofollow" class="external free" href="http://free-images-etc.rb-d.com/wp-content/uploads/IMG_9043.jpg">http://free-images-etc.rb-d.com/wp-content/uploads/IMG_9043.jpg</a>
</p><p>Neon Spectral Lines
Credit: Wikimedia Commons user Jan Homann
<a href="//commons.wikimedia.org/wiki/File:Hydrogen_Emission_Spectrum.svg" title="File:Hydrogen Emission Spectrum.svg">File:Hydrogen_Emission_Spectrum.svg</a>
</p><p>Hydrogen Spectral Lines
Credit: Wikimedia Commons user Jkasd
<a href="//commons.wikimedia.org/wiki/File:Hydrogen_Emission_Spectrum.svg" title="File:Hydrogen Emission Spectrum.svg">File:Hydrogen_Emission_Spectrum.svg</a>
</p><p>Interacting Galaxies UGC 8835
Credit: NASA, ESA, the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration, and A. Evans (University of Virginia, Charlottesville/NRAO/Stony Brook University)
<a rel="nofollow" class="external free" href="http://hubblesite.org/newscenter/archive/releases/2008/16/image/ah/">http://hubblesite.org/newscenter/archive/releases/2008/16/image/ah/</a>
</p><p>Barnard's Star Proper Motion
Credit: Steve Quirk
<a class="external free" href="https://commons.wikimedia.org/wiki/File:Barnard2005.gif">http://commons.wikimedia.org/wiki/File:Barnard2005.gif</a>
</p><p>Stellar Deep Field
Credit: NASA, ESA and T.M. Brown (STScI)
<a rel="nofollow" class="external free" href="http://hubblesite.org/newscenter/archive/releases/2003/15/image/a/">http://hubblesite.org/newscenter/archive/releases/2003/15/image/a/</a>
</p><p>Milky Way and Andromeda Collision Scenario
Credit: NASA, ESA, and A. Feild and R. van der Marel (STScI)
<a rel="nofollow" class="external free" href="http://hubblesite.org/newscenter/archive/releases/2012/20/image/m/">http://hubblesite.org/newscenter/archive/releases/2012/20/image/m/</a>
</p><p>Milky Way, Andromeda, Triangulum Encounter Visualization
Visualization Credit: NASA, ESA, and F. Summers (STScI)
Simulation Credit: NASA, ESA, G. Besla (Columbia University), and R. van der Marel (STScI)
<a rel="nofollow" class="external free" href="http://hubblesite.org/newscenter/archive/releases/2012/20/video/j/">http://hubblesite.org/newscenter/archive/releases/2012/20/video/j/</a>
</p><p>Music "Stars"
Credit: Shamil Elvenheim (CC-BY-NC-SA 3.0)
<a rel="nofollow" class="external free" href="http://freemusicarchive.org/music/Shamil_Elvenheim/strolling_through_electronic_spaces/13_-_Shamil_Elvenheim_-_Stars">http://freemusicarchive.org/music/Shamil_Elvenheim/strolling_through_electronic_spaces/13_-_Shamil_Elvenheim_-_Stars</a>
</p><p>Earth in Hammer-Aitoff Projection
Credit: Wikimedia Commons user Strebe
<a href="//commons.wikimedia.org/wiki/File:Aitoff_projection_SW.jpg" title="File:Aitoff projection SW.jpg">File:Aitoff_projection_SW.jpg</a>
</p><p>Milky Way, Andromeda, Triangulum Encounter Visualization - Hammer-Aitoff Projection
Visualization Credit: F. Summers (STScI)
Simulation Credit: G. Besla (Columbia University), and R. van der Marel (STScI)
</p><p>Illustrative Sky Views of the Milky Way-Andromeda Collision
Credit: NASA, ESA, Z. Levay, R. van der Marel, and G. Bacon (STScI), T. Hallas, and A. Mellinger
<a rel="nofollow" class="external free" href="http://hubblesite.org/newscenter/archive/releases/2012/20/video/d/">http://hubblesite.org/newscenter/archive/releases/2012/20/video/d/</a>
</p><p>Andromeda Constellation
Credit: A. Fujii (used with permission)
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<a rel="nofollow" class="external free" href="http://www.davidmalin.com/fujii/fujii_index.html">http://www.davidmalin.com/fujii/fujii_index.html</a>
NASA / Hubble Space Telescope team
2013-04-05
<a rel="nofollow" class="external free" href="http://hubblesite.org/explore_astronomy/hubbles_universe_unfiltered/episodes/17">http://hubblesite.org/explore_astronomy/hubbles_universe_unfiltered/episodes/17</a> (also <a rel="nofollow" class="external autonumber" href="https://www.youtube.com/watch?v=r8YQsFZyGzw">[1]</a>)