Evidence Hub

A never-ending story in the sky: The secrets of chemical evolution

Puzzarini C, Barone V

Physics of life reviews, 2020

Abstract

Cosmic evolution is the tale of progressive transition from simplicity to complexity. The newborn universe started with the simplest atoms formed after the Big Bang and proceeded toward the formation of the so-called 'astronomical complex organic molecules' (aCOMs), most of them showing a clear prebiotic character. Understanding the chemical evolution of the universe is one of the main aims of Astrochemistry, with the starting point being the knowledge whether a molecule is present in the astronomical environment under consideration and, if so, its abundance. However, the interpretation of astronomical detections and the identification of molecules are not at all straightforward. Indeed, the extraterrestrial chemical inventory has been obtained by means of astronomical observations based on spectroscopic signatures determined in laboratory (either experimental or computational) studies. Even though the presence of aCOMs has been known for decades, the processes that lead to their synthesis are still hotly debated or even unknown. It is often assumed that aCOMs are mostly synthesized on grain surfaces during the so-called warm-up phase, when various radicals trapped in the grain mantles acquire mobility and recombine into large molecules. However, recent detections of aCOMs in cold environments have challenged this exclusive role of grain-surface chemistry. Clearly, gas-phase chemistry is at work in cold environments. Moving to Titan's atmosphere, prior to the Cassini-Huygens…

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free