NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Mid- and far-infrared spectroscopic studies of the influence of temperature, ultraviolet photolysis and ion irradiation on cosmic-type icesInfrared (IR) studies of laboratory ices can provide information on the evolution of cosmic-type ices as a function of different simulated space environments involving thermal, ultraviolet (UV), or ion processing. Laboratory radiation experiments can lead to the formation of complex organic molecules. However, because of our lack of knowledge about UV photon and ion fluxes, and exposure lifetimes, it is not certain how well our simulations represent space conditions. Appropriate laboratory experiments are also limited by the absence of knowledge about the composition, density, and temperature of ices in different regions of space. Our current understanding of expected doses due to UV photons and cosmic rays is summarized here, along with an inventory of condensed-phase molecules identified on outer solar system surfaces, comets and interstellar grains. Far-IR spectra of thermally cycled H2O are discussed since these results reflect the dramatic difference between the amorphous and crystalline phases of H2O ice, the most dominant condensed-phase molecule in cosmic ices. A comparison of mid-IR spectra of products in proton-irradiated and UV-photolyzed ices shows that few differences are observed for these two forms of processing for the simple binary mixtures studied to date. IR identification of radiation products and experiments to determine production rates of new molecules in ices during processing are discussed. A new technique for measuring intrinsic IR band strengths of several unstable molecules is presented. An example of our laboratory results applied to Europa observations is included.
Document ID
20040112453
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Moore, M. H.
(NASA Goddard Space Flight Center Greenbelt MD United States)
Hudson, R. L.
Gerakines, P. A.
Date Acquired
August 21, 2013
Publication Date
March 15, 2001
Publication Information
Publication: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy
Volume: 57
Issue: 4
ISSN: 1386-1425
Subject Category
Lunar And Planetary Science And Exploration
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available