Chemistry

Biographical Info

There is growing evidence that the molecules necessary for the evolution of life on earth arrived here from the interstellar medium. The study of these molecules is therefore one of great current interest. To date, over one hundred and twenty molecules have been found to exist in interstellar space. Most of these molecules have been detected by radioastronomy, but others have been found by visible/ultraviolet or infrared spectroscopy. There are two major types of signals from interstellar space that have intrigued and puzzled astronomers, astrophysicists, and astrochemists. They are the so-called “unidentified” interstellar infrared emission bands (UIRs) and the diffuse interstellar absorption bands (DIBs). Both have been known for many years, the former for about 30 years and the latter for about 80 years, but the species responsible for them have not yet been found, despite much research. Early on, the thought was that the carriers of these bands were small grains, but, in recent times, it has been agreed that a gas phase molecule-like species is more likely. The conditions under which these molecular species must survive are stark. Temperatures can be extremely cold (10-100K) except, of course, near stars. Pressures are generally lower than any produced here on earth. And the radiation present can run the gamut from microwaves to X-rays and beyond.