The Milky Way could be spreading life from star to star
(PHYSorg.com Space & Earth)

For almost two centuries, scientists have theorized that life may be distributed throughout the universe by meteoroids, asteroids, planetoids, and other astronomical objects. This theory, known as Panspermia, is based on the idea that microorganisms and the chemical precursors of life are able to survive being transported from one star system to the next.