Complex organic molecules in comets from remote-sensing observations at millimeter wavelengths

TL;DR

This paper reviews the detection of complex organic molecules in comets via millimeter spectroscopy, highlighting their abundance and implications for understanding the solar system's presolar material.

Contribution

It provides a comprehensive overview of the detection and abundance measurement of COMs in comets using high-resolution millimeter spectroscopy, emphasizing their significance.

Findings

Over 25 molecules detected in comets over twenty years.

COM abundances in comets are similar to those in star-forming regions.

Upper limits constrain the presence of certain COM isomers.

Abstract

Remote observations of comets, especially using high spectral resolution millimeter spectroscopy, have enabled the detection of over 25 molecules in comets for the last twenty years. Among the molecules identified at radio wavelengths, complex organic molecules (COMs) such as acetaldehyde, ethylene-glycol, formamide, methyl-formate or ethanol have been observed in several comets and their abundances relative to water and methanol precisely determined. Significant upper limits on the abundance of several other COMs have been determined and put constraints on the dominant isomer for three of them. The abundances measured in comets are generally of comparable order of magnitude as those measured in star-forming regions, suggesting that comets contain preserved material from the presolar cloud from which the solar system was born.