Interstellar Molecules and Interstellar Chemistry

Abstract

Radio astronomers have to date detected some 60 or so molecules in interstellar space. These molecules have been identified, in the majority of cases, by recording the microwave spectrum received by radio telescope from an interstellar or circumstellar dust cloud and comparing it with the spectra produced in laboratory experiments. This provides a reliable technique for the identification of molecules in space that are well known in the laboratory. However, radio astronomers and microwave spectroscopists recognized that some of the spectra received from space did not correspond to molecules known on Earth. This is perhaps not very surprising, since the prevalent conditions in space are very different from those in the terrestrial laboratory. It is in the study of interstellar molecules which are not observed on Earth that we find the main applications of the techniques of computational chemistry in astronomy.