What existed before the first living organism? In this episode of COSMOS, we explore one of science's greatest mysteries: how could life emerge from non-living matter?

The conversation begins with a deceptively simple question: can molecules associated with life—such as amino acids, proteins, sugars, and carbohydrates—form without living organisms?

From there, we explore the chemistry of early Earth, the role of water, the enormous complexity of protein formation, and why the probability of randomly assembling a modern protein does not necessarily tell us the probability of abiogenesis.

We then examine panspermia: the possibility that life or its precursors may have originated elsewhere and reached Earth. But if life came from somewhere else, where did it originally come from?

Finally, we consider the deeper mystery: how c ...