Andromeda: Our Sister Galaxy
Category: SCIENCE
By measuring very precisely the motion of the Andromeda galaxy relative to the Milky Way, astronomers using the Hubble Space Telescope were able to determine in 2012 that the Milky Way and Andromeda are destined for a head-on collision in about 4 billion years.
By Mario Livio, ContributorAstrophysicist, 2015-01-21