Building galaxies
Monday, July 11, 2011 - 12:00
in Astronomy & Space
(PhysOrg.com) -- Galaxies frequently collide with one another. Our own Milky Way galaxy, for example, and its nearest giant neighbor, the Andromeda galaxy, are heading towards each other at a rate of about 120 kilometers per second; predictions claim the two will merge together in another four billion years or so.