  The origin of complex organic molecules such as amino acids and their
precursors found in meteorites and comets is unknown. Previous studies have
accounted for the complex organic inventory of the Solar System by aqueous
chemistry on warm meteoritic parent bodies, or by accretion of organics formed
in the interstellar medium. This paper proposes a third possibility: that
complex organics were created in situ by ultraviolet light from nearby O/B
stars irradiating ices already in the Sun's protoplanetary disk. If the Sun was
born in a dense cluster near UV-bright stars, the flux hitting the disk from
external stars could be many orders of magnitude higher than that from the Sun
alone. Such photolysis of ices in the laboratory can rapidly produce amino acid
precursors and other complex organic molecules. I present a simple model
coupling grain growth and UV exposure in a young circumstellar disk. It is
shown that the production may be sufficient to create the Solar System's entire
complex organic inventory within 10^6 years. Subsequent aqueous alteration on
meteoritic parent bodies is not ruled out.
