Physics: NASA/AMES Researchers in Mountain View, California. D. Hudgins, J Dworkin, M. Berstein (Left to Right). Looking for P.A.H. in the lab at Nasa Ames. Polycyclic Aromatic Hydrocarbons (PAHs) are a class of very stable organic molecules made up of only carbon and hydrogen. Photographed at NASA's Ames Research Center, California, USA.- Origin of Life 1999.