The infrared spectra of dense molecular clouds provide evidence that the ices in these interstellar enviornments are often processed by ionizing radiation. In the Astrochemistry Laboratory we carry out laboratory simulations of this processing on analog materials using a variety of sophisticated instruments. These studies have demonstrated that the UV irradiation of even very simple ices can result in the production of refractory organic residues. Organics with similar spectral characteristics are seen throughout the diffuse interstellar medium. Our laboratory photolysis residues contain complicated mixtures of more complex organic molecules, including compounds that may be of great prebiotic interest, for example, compounds that form membranes and compounds that fluoresce.

The production of these more complex organics from such simple starting materials as ices of H₂O, CH₃OH, and NH₃ is an observation of great importance. Dense molecular clouds are seen to exist throughout our and other galaxies. Thus, the processes being studied in our and other laboratories are universal ones, i.e., the universe is in some sense hardwired to produce large quantities of prebiotic organic materials. Furthermore, it is in these interstellar clouds that new stars and new planetary systems are formed. The result is the virtual assurance that when new planetary systems are formed, prebiotic organics will be present in the starting materials. If some of these materials survive incorporation onto suitable planets, they may play a key role in the start of life. This is a possiblity that is receiving a great deal of attention of late and one that is a guiding theme for many of our studies. We are currently making some very interesting progress in this area and we invite you to keep your eye on this page in the future!

Some of this material is discussed in more detail in a chapter in a recent book on the Origin of Life or an article in The New Scientist, and in our press release about vesicle formation.

For more detailed information on our laboratory work on the organics produced by the UV irradiation of astrophysical ices, see:

Dworkin J.P., D. W. Deamer, S. A. Sandford, L. J. Allamandola “Self-Assembling Amphiphilic Molecules: Synthesis in Simulated Interstellar/Precometary Ices” Proceedings of the National Academy of Science, USA. 98: 815-819.

Bernstein, M. P., Sandford, S. A., Allamandola, L. J., Gillette, J. S., Clemett, S. J., & Zare, R. N. (1999). UV Irradiation of Polycyclic Aromatic Hydrocarbons in Ices: Production of Alcohols, Quinones, and Ethers. Science 283, 1135-1138.

Salama, F. (1998). The Diffuse Interstellar Bands: A Tracer For Organics in the Diffuse Interstellar Medium? Origins Life Evol. Biosphere 28, 349-364.

Allamandola, L. J., Bernstein, M. P., & Sandford, S. A. (1997). Photochemical evolution of interstellar/precometary organic material. In Astronomical and Biochemical Origins and the Search for Life in the Universe, C.B. Cosmovici, S. Bowyer, & D. Werthimer (eds.), Proc. 5th International Conf. on Bioastronomy, IAU Coll. #161, Capri, 1-5 July 1996, (Editrice Compositori: Bologna), pp. 23-47.

Bernstein, M. P., Sandford, S. A., Allamandola, L. J., Chang, S., & Scharberg, M. A. (1995). Organic Compounds Produced by Photolysis of Realistic Interstellar and Cometary Ice Analogs Containing Methanol. Astrophys. J. 454, 327-344.

Allamandola, L. J., Sandford, S. A., & Valero, G. (1988). Photochemical and thermal evolution of interstellar/pre-cometary ice analogs. Icarus 76, 225-252.