Now is a good time to talk about panspermia.
Panspermia is an idea first seriously promoted
by Sir Fred Hoyle and Chandra Wickramasinghe,
in 1974.
Panspermia is the idea that rather than life forming
in situ on Earth, it formed elsewhere and was
delivered to Earth via some kind of interplanetary
or interstellar transportation -- probably a comet or asteroid.