Our Night Sky When We Collide With Andromeda
In the photos above in order:
— Present day
— 2 Billion years from now the of the approaching Andromeda galaxy is noticeably larger
— 3.75 Billion years, Andromeda fills the field of view
— 3.85 Billion years, the sky is ablaze with new star formation
— 3.9 Billion years, star formation continues
— 4 Billion years, Milky Way is warped and Andromeda is tidally stretched
— 5.1 Billion years, cores of both galaxies appear as a pair of globes
— 7 Billion years, the cores have merged, the bright core dominates the night skyHere is an animation of the collision
In around 4 billion years our galaxy, The Milky Way, will collide with our neighbor galaxy Andromeda or M31. You might think this will be a catastrophic event for everything in the galaxy including our solar system but in reality most of the solar systems will simply pass by each other. However, given the new galactic center and the new mass pulling everything towards it and tossing it around, the orbits of those solar systems will be changed.
The massive Andromeda galaxy is about 120,000 light years across while our galaxy is 100,000 light years across. Given their size, the speed that we our hurdling towards each other is relatively small at 250,000 miles per hour.
Sources:
http://www.nasa.gov/mission_pages/hubble/science/milky-way-collide.html
http://www.nasa.gov/multimedia/imagegallery/image_feature_1837.html
Big things have small beginnings.
