Panspermia

Panspermia: Historically, panspermia was a theory according to which life was propagated through the universe in interstellar space in the form of germs, spores or seeds driven by the pressure of light. Currently, some theories on theorigin of life on Earth rely on meteorites or comets bearing organic molecules. Thus according to this hypothesis, meteorites or comets would have brought the essential components of life to Earth.