Organic Material in the Outer Solar System and Interstellar Medium
 Organic material may be created in dense molecular clouds on the surface of icy dust grains by UV-driven chemistry. Dust agglomerates with their inventory of organic molecules may find their way into planet-forming regions |
Organic material is found in both our solar system (in asteroids, comets, meteorites and dust) as well as the
interstellar medium, but it is not known if these non-terrestrial organic materials have a similar origin. In
laboratory experiments, amino acids and complex organic residues have been created by intense ultraviolet
illumination of an icy grain type of surface. Organic material is thought to be created in dense molecular clouds
on the surface of dust grains that catalyze ultraviolet-driven chemistry. The organic residue then acts as a "glue"
and the grains stick together, helping to protect the fragile organic material from destruction when the grains are
exposed to radiation. The icy surfaces of cometary and meteoritic matter are expected to display a type of
organic chemistry similar to that in dust when irradiated by ultraviolet radiation or high-energy particles such as
cosmic rays.
It is known that organic material from small bodies reaches Earth. Amino acids have been found in meteorites, and have been tentatively identified in the interstellar medium in the region of our galaxy known as Sagittarius B2. It has been suggested that interstellar matter forming the protoplanetary disk of our solar system may have supplied organic material to the early Earth via comets and meteoroids formed from aggregates of interstellar solids, but the possible role of these processes in the emergence of life on our planet is uncertain. A suitable instrument on Interstellar Probe would be able to search for organic material in the outer solar system, as well as the nearby interstellar medium, in order to address questions about the nature and chemical evolution of this material. The dust detector on the Giotto mission to Halley's comet identified grains that were composed almost entirely of H, C, N, and O. If on-going instrument development efforts are successful, Interstellar Probe could carry instrumentation with greatly improved capability to identify organic materials. |
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Introduction
Interstellar Medium
Interaction Between the Interstellar Medium and the Solar Wind
The Outer Solar System
Scientific Instruments and Mission Requirements
Acknowledgments
Table of Contents
For more information regarding this website
and the Interstellar Probe Project,
please contact Dr. Paulett Liewer
This site was last updated:
February 8, 2000.
