At present, in 2014, my principal activity in astrochemistry and astrobiology is as an editor of the Encyclopedia of Astrobiology, published by Springer.
I began my research career in astronomy with a dissertation in cosmology, specifically on the growth of structure in the expanding universe. A result was what has been called the Layzer-Irvine, or the Cosmic Energy, equation. A post-doctoral position at the Leiden Observatory in the Netherlands subsequently led me into those aspects of planetary and atmospheric science dealing with the transmission and reflection of radiation by atmospheres and rough surfaces, including what has been called the Hapke-Irvine law or relation.
After the establishment of the Five College Radio Astronomy Observatory, particularly the 14-meter diameter millimeter-wave telescope at the University of Massachusetts Amherst, my research switched into two new areas: the chemistry of dense interstellar clouds and the physics and chemistry of comets. Dense interstellar clouds are the most massive objects in the universe consisting of material subject to the chemical bond. The composition and the processes determining this composition are thus of fundamental importance to our understanding of the universe. As the chemical composition affects the heating and cooling processes of the cloud, there is a tight evolutionary link between chemistry, cloud physics and evolution, and star formation.
Although by far the most abundant molecular species in these clouds is molecular hydrogen, the trace constituents exhibit a complex organic (carbon-based) chemistry. At the least demonstrating that organic chemistry is widespread in the universe, this composition raises the question of what role interstellar organics might have played in the origin of life on Earth or elsewhere --- thus, this research becomes a part of astrobiology. An aspect of these studies is the search for and identification of new interstellar molecules. My colleagues and I have played a role in the discovery of some 13 such new molecular species, involving collaborations with astronomers
at Nobeyama Radio Observatory in Japan and the Onsala Space Observatory in Sweden.
The same radio techniques at millimeter and submillimeter wavelengths used to study interstellar matter are also useful in observing comets, the least processed material surviving from the origin of the solar system. Observations of cometary organic molecules can give information on cometary physics and the relation of comets to interstellar material. Since comets were clearly a source of organic matter for the early Earth, studying the nature and links between the organic chemistry in interstellar clouds and in comets is an important aspect of astrobiology.