Predicting products of space ice chemistry

Abstract

In the search for sources of complex organic molecules in space, some researchers have turned to hydrocarbon ices, which exist in interstellar space and on bodies in our solar system, such as Saturn’s moon Titan. Experiments have shown that high-energy electrons generated by ionizing radiation can induce formation of complex organic molecules on these ices. However, researchers still aren’t sure which chemicals form inside of the ices and which form on their surface or in nearby gases. Existing models of space chemistry can’t predict the products of such reactions. At the ACS meeting last week, researchers reported that they used tunable lasers to identify which isomers of small hydrocarbon molecules form within methane ice in laboratory experiments simulating interstellar conditions. Matthew Abplanalp, a graduate student in Ralf I. Kaiser’s group at University of Hawaii, Manoa, and colleagues held methane ice at 5.5 K inside an ultrahigh vacuum, bombarded it with