The theory of Panspermia states that life exists through the cosmos, and is distributed between planets, stars and even galaxies by asteroids, comets, meteors and planetoids. In this respect, life began on Earth about 4 billion years ago after microorganisms hitching a ride on space rocks landed on the surface. Over the years, considerable research has been devoted towards demonstrating that the various aspects of this theory work.
The origin of life on Earth has been a matter of intense debate throughout human history. Even today, scientists don’t know whether the molecular building blocks of life were created on Earth or whether they were brought here by comets and meteorites. This is obviously hugely important – if they were delivered to Earth then it seems plausible that they may have been transported to other planets, too.