Robert F. Ferrante
Professor
Ph.D., University of Florida
(410) 293-6623
Chemistry Department
U.S. Naval Academy
572M Holloway Road
Annapolis, MD 21402-5026
Research Interests
Professor Ferrante's research examines the properties of molecules at low temperatures. A primary research interest lies in the use of spectroscopic techniques (IR, UV/Vis, ESR) for the elucidation of the geometric and electronic structures of unstable or highly reactive molecules, both organic and inorganic. Such molecules appear as intermediates or degradation fragments in chemical or photochemical reactions, or can be found in the vapors over refractory solids, in stellar atmospheres, or in other high temperature environments. These very reactive species can be observed in the laboratory by use of the matrix-isolation technique, which entails trapping them in an inert solid host (typically solid Ar or N2) at very low temperatures (near 10 K). Under such conditions, these highly unusual molecules can be preserved indefinitely, and their spectra can be readily obtained and examined for structural and mechanistic implications.
Most of his recent work involves low temperature spectroscopic studies of samples related to comets, molecular clouds, or outer solar system bodies. This laboratory work is designed to provide data to model the observed or predicted molecular composition and thermal- or radiation-processing behavior of ices that exist in these astrophysical environments. Here, the ices are stable molecules like water or methane, maintained at temperatures appropriate to the object (35K-150K). Measurements include the determination of the “optical constants”, the real (n) and imaginary (k) components of the refractive index of the material. These are calculated from high resolution FTIR spectra, and the refractive indices measured by a two-laser interferometric method. Such ices have also been exposed to UV radiation or 1 MeV protons to simulate cosmic ray exposure. The radiation creates new molecules, which can be identified by FTIR spectroscopy. Additional chemical reactions and phase changes can occur as the samples are warmed. These laboratory results, when compared to observational data (from both earth-based telescopes and space probes), provide insight into the history and development of these distant objects. This work is performed at the NASA/Goddard Space Flight Center. Check out the Cosmic Ice Laboratory web site http://science.gsfc.nasa.gov/
