File:Clash of the Titans.webm

English: 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.

"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.

HubbleSite page: http://hubblesite.org/explore_astronomy/hubbles_universe_unfiltered/episodes/17

• Notes

NASA's Hubble Shows Milky Way is Destined for Head-on Collision with Andromeda Galaxy: http://hubblesite.org/newscenter/archive/releases/2012/20/

Milky Way drawing Credit: NASA, JPL-Caltech, R. Hurt (SSC-Caltech) http://www.spitzer.caltech.edu/images/1923-ssc2008-10a-A-Roadmap-to-the-Milky-Way

Milky Way panorama Copyright: Axel Mellinger (used with permission) http://home.arcor-online.de/axel.mellinger/

Large Magellanic Cloud Credit: David Malin Copyright: Australian Astronomical Observatory (used with permission) http://www.aao.gov.au/images/captions/uks014.html

Small Magellanic Cloud Credit: NOAO/AURA/NSF http://www.noao.edu/image_gallery/html/im0563.html

Andromeda Galaxy Credit: Bill Schoening, Vanessa Harvey/REU program/NOAO/AURA/NSF http://www.noao.edu/image_gallery/html/im0424.html

Triangulum Galaxy Credit: T.A.Rector (NRAO/AUI/NSF and NOAO/AURA/NSF) and M.Hanna (NOAO/AURA/NSF) http://www.noao.edu/image_gallery/html/im0775.html

Local Group Schematic Credit: Christine Godfrey

Visible Light Spectrum Credit: Wikimedia Commons user Philip Roman File:EM_spectrum.svg

Neon Pizza Sign http://free-images-etc.rb-d.com/wp-content/uploads/IMG_9043.jpg

Neon Spectral Lines Credit: Wikimedia Commons user Jan Homann File:Hydrogen_Emission_Spectrum.svg

Hydrogen Spectral Lines Credit: Wikimedia Commons user Jkasd File:Hydrogen_Emission_Spectrum.svg

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) http://hubblesite.org/newscenter/archive/releases/2008/16/image/ah/

Barnard's Star Proper Motion Credit: Steve Quirk http://commons.wikimedia.org/wiki/File:Barnard2005.gif

Stellar Deep Field Credit: NASA, ESA and T.M. Brown (STScI) http://hubblesite.org/newscenter/archive/releases/2003/15/image/a/

Milky Way and Andromeda Collision Scenario Credit: NASA, ESA, and A. Feild and R. van der Marel (STScI) http://hubblesite.org/newscenter/archive/releases/2012/20/image/m/

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) http://hubblesite.org/newscenter/archive/releases/2012/20/video/j/

Music "Stars" Credit: Shamil Elvenheim (CC-BY-NC-SA 3.0) http://freemusicarchive.org/music/Shamil_Elvenheim/strolling_through_electronic_spaces/13_-_Shamil_Elvenheim_-_Stars

Earth in Hammer-Aitoff Projection Credit: Wikimedia Commons user Strebe File:Aitoff_projection_SW.jpg

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)

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 http://hubblesite.org/newscenter/archive/releases/2012/20/video/d/

Andromeda Constellation Credit: A. Fujii (used with permission)

http://www.davidmalin.com/fujii/fujii_index.html