This video zooms into a region in the halo of the neighboring Andromeda galaxy that astronomers studied with the Hubble Space Telescope to make precise measurements of the galaxy's motion. Andromeda was previously known to be approaching the Milky Way, but these new measurements of Andromeda's lateral (or sideways) motion can be used to predict that the galaxy is destined for a head-on collision with our Milky Way. Images of the same halo field taken seven years apart were used to precisely measure the tiny amount of motion relative to background galaxies. When this shift is projected over the next 32,000 years the motion on the sky becomes apparent.
Publication: May 31, 2012