Skip to main content
Collision Course

Myth vs Reality: Galaxy Collisions

 This short video addresses the misconception that all galaxies move away from each other.

Credits

Colliding Galaxies
 
 
Produced by the Space Telescope Science Institute’s Office of Public Outreach.
 
All images, illustrations, and videos courtesy of NASA, ESA, and STScI except:
 
·       Taurus constellation drawing from Firmamentum Sobiescianum sive Uranographia by Johannes Hevelius, courtesy of the United States Naval Observatory
·       Large galaxy collision animation courtesy of NASA/Goddard Space Flight Center and the Advanced Visualization Laboratory at the National Center for Supercomputing Applications, B. Robertson, L. Hernquist
·       Expanding universe animation courtesy of NASA
·       Andromeda Galaxy image courtesy of Digitized Sky Survey 2, acknowledgment: Davide De Martin (ESA/Hubble)
·       Animated pan through Milky Way courtesy of ESO/M. Kornmesser
·       Animation of stars moving courtesy of Frank Summers (STScI)
·       Animation of random stellar orbits courtesy of NCSA, UCLA/Keck
·       Milky Way formation animation ©Prof. Romain Teyssier (University of Zurich)
·       Major and minor galaxy merger animations ©Dr. Benjamin Moster (Max-Planck-Institute for Astrophysics)
·       Fly-around animation of Sagittarius Dwarf Galaxy courtesy of David Law (Dunlap Institute, University of Toronto)
·       Animation of two colliding spiral galaxies courtesy of Volker Springel, Max-Planck-Institute for Astrophysics
 
 
Written by Vanessa Thomas and John Stoke
Designed by John Godfrey and Marc Lussier
Music courtesy of Association Production Music

Transcript

(SPEECH) 
 [ELECTRONIC MUSIC] 


(DESCRIPTION) 
 Top left, a black and white picture of a minotaur. Top right, a color picture of galaxies. 


Text, MYTH versus REALITY 


Myth side 


Text, Because the universe is expanding, all galaxies are moving away from one another. 


Reality side 


Text, If galaxies are close enough to each other, their mutual gravitational pull can overcome the expansion of the universe and keep the galaxies together in a group or cluster. In fact, if galaxies are too close, gravity can pull them toward one another until they collide.