Delivery of Complex Organic Compounds from Planetary Nebulae to the Solar System

Infrared spectroscopic observations of planetary nebulae and proto-planetary nebulae have shown that complex organic compounds are synthesized in these objects over periods as short as a thousand years. These compounds are ejected into the interstellar medium and spread throughout the Galaxy. Evidence from meteorites has shown that these stellar grains have reached the Solar System, and may have showered the Earth during the heavy bombardment stage of the Early Earth. In this paper, we discuss the chemical structure Of Stellar organic grains and compare them to the organic matter found in meteorites, comets, asteroids, planetary satellites, and interplanetary particles. The possibility that the early Solar System was chemically enriched by organic compounds ejected from distant stars is presented.