Science Alert reports:

Where did we come from? The answer, many scientists have proposed, is space.

One longstanding theory, hypothesized for over a century, is that life on Earth emerged from fragments of prebiotic chemistry that arrived from the cosmic unknowns, possibly delivered by far-flung comets.

The idea is supported by a growing body of evidence, with scientists detecting signs of organic molecules in comets soaring through space, which hypothetically could seed the ingredients of life on worlds they come into contact with.

But according to new simulations, the chances of this actually happening are so improbable they’re bordering on science fiction.

“It’s kind of a romantic idea, but our results suggest it’s highly unlikely,” says astronomer Richard Anslow from the University of Cambridge.

In a new study in Scientific Reports, Anslow and fellow researchers ran simulations to test what would happen if comets, as hypothesized, did in fact carry prebiotic chemicals to Earth. [Continue reading…]