What is life? It’s a fuzzy concept without a single answer. If you asked a philosopher, they might quote Plato and tell you it’s the ability to support yourself and reproduce, though that would make sterile donkeys non-living objects. Ask a biologist and they’ll likely hit you with a textbook definition of life as organized matter with genes—as diverse as a paramecium and an elephant.  

Oliver Trapp, a professor of chemistry at the Ludwig Maximilian University of Munich in Germany, offers a different description. He says life is a “self-sustainable reaction network,” in which organisms have the processes necessary to survive and adapt. This is in line with the definition NASA uses when looking for extraterrestrial life. Having a clear idea of what makes up life, and the conditions needed to sustain it, helps astronomers get a better picture of what to look for when searching for life on other planets. 

Specifically, they could look for the environments that have collected the essential ingredients. Prerequisites to making life, based on what happened during early Earth, are materials for organic chemical reactions. In a new study published today in Scientific Reports, Trapp and his colleagues simulated how our planet received the supplies for life-producing chemical reactions 4.4 billion years ago. They suggest that no special or lucky conditions were necessary. Instead, life on Earth was created from volcanic particles and iron-rich meteorites. These carried the building blocks essential to living things: amino acids, lipids, nucleosides, and sugars.

To read more, click here.