Abstract

In the RNA World hypothesis, it is generally assumed that self-replicating RNA emerged from a primordial soup of amino acids approximately 500 million years before the advent of life on Earth. Recently, prebiotic molecules such as glycolaldehyde and amino acetonitrile have been discovered in abundance in nebulae like Sagittarius B2. This paper proposes that icy grains within these nebulae could act as primordial soups and explores the implications of this hypothesis. It is argued that the sheer abundance of these grains in a typical nebula makes their collective volume astronomically greater than Earth’s primitive oceans, thus favouring the likelihood of an RNA self-replicator emerging within this environment based on volume arguments. The likelihood of naturally producing the first self-replicator may be significantly lower than previously envisioned, necessitating the contribution of a larger primordial soup spread across a nebula and functioning for billions of years before the emergence of life on Earth. According to this model, Earth could have been seeded by panspermia following the emergence of a self-replicator on nearby icy interstellar dust. Finally, we discuss the Fermi paradox in the context of this model.