Laboratory Astrochemistry: A Powerful Tool to Understand the Origin of Organic Molecules in the Interstellar Medium, Comets, and Meteorites

During the past two decades, astrochemistry laboratory simulations have shown that complex organic molecules can be formed under simulated astrophysical conditions from the vacuum ultraviolet (UV) irradiation of ice mixtures containing simple species such as H 2 O, CO, CO 2 , CH 3 OH, and NH 3 .These organics include compounds of biological and prebiotic interests such as amino acids-the building blocks of proteins, and nucleobases-the informational subunits of DNA and RNA.Although the presence of amino acids in the interstellar medium (ISM) has not been confirmed by observations to date, they have been detected in meteorites, indicating that biomolecules and/or their precursors can be formed under extraterrestrial, non-biological conditions.Nucleobases have also been detected in meteorites, broadening the variety of complex organic molecules that can be formed in astrophysical environments.Like amino acids, nucleobases and other N-heterocycles have not been observed in the ISM.In the following, I will review some of the progress made by laboratory astrochemistry towards understanding the formation of organic species from the UV irradiation of ices at low temperature under astrophysically relevant conditions.This discussion will be focused on the formation of amino acids and other molecules of prebiotic interest such as urea and glycerol.Then, I will present recent studies on the formation of nucleobases and related compounds from the UV irradiation of pyrimidine in H 2 O, NH 3 , and CH 3 OH ices, which show the formation of a large suite of photo-products including the nucleobases uracil and cytosine.Frank N.