PDS: The Planetary Atmospheres NodePlanetary Atmospheres
Cover Page/Proposal Summary
ROSS-00 NRA 00-OSS-01
Date Due: 4/28/2000
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This proposal shall be used and disclosed for evaluation purposes only, and a copy of this Government notice shall be applied to any reproduction or abstract thereof. Any authorized restrictive notices that the submitter places on this proposal shall also be strictly complied with. Disclosure of this proposal for any reason outside the Government evaluation purposes shall be made only to the extent authorized by the Government. |
| Proposal Type: New Proposal |
| Proposal Category: Laboratory |
| Major Equipment Proposal? No |
| Do you intend to submit an Education/Public Outreach (E/PO) proposal? No |
| Proposal Title: |
| Thermodynamic Properties of Planetary Molecules at Low Temperatures |
| Abbreviated Proposal Title: |
| Low-Temperature Molecular Thermodynamic Properties |
| Principal Investigator: |
| Dr. John Allen Jr. Astrochemistry Branch/ Laboratory for Extraterrestrial Physics/ CODE 691 NASA's Goddard Space Flight Center Greenbelt, MD 20771-0001 Phone: 301-286-5896 Fax: 301-286-0212 E-mail: john.e.allen@gsfc.nasa gov |
| Signature | Date |
| _____________________________________ | ____________ |
| Co-Investigators and Collaborators: | |||
| Type | Name | Affiliation | |
| Sci Co-I | Prof. Robert N. Nelson | Georgia Southern University | robert.n.nelson@gasou.edu |
Proposal Summary:
Interpretation of planetary observations and modeling of planetary atmospheres are critically dependent on accurate laboratory data for the properties and processes of the various constituents that are responsible for characteristic atmospheric features and phenomena. It is important that these data be taken over the appropriate range of parameters, e.g., temperature, pressure, and composition; however, temperature-dependent laboratory data for most properties or processes of the relevant species are particularly meager. This proposal addresses the needs of the planetary atmospheres community for thermodynamic properties of planetary molecules at low temperatures. These data serve as input for fundamental parameters in composition and thermal-structure models of planetary atmospheres. In the absence of low-temperature measurements, modelers must extrapolate high-temperature data to the temperatures of interest. These extrapolations can cover large temperature ranges, thus introducing significant errors in the models. We propose to measure thermodynamic properties for a series of light hydrocarbons and small inorganic molecules at temperatures appropriate for the outer planets and their satellites. Thermodynamic quantities – vapor pressures for single species and fugacities for binary mixtures - at low temperatures will be determined using an apparatus that was specifically designed and constructed for these purposes. During this proposal period the vapor pressures of sulfur dioxide and hydrogen cyanide as single components and the partial pressures of methane and nitrogen in binary mixtures will be measured for temperatures ranging from 62 to 240 K. Results from these experiments will be of immediate use in atmospheric models constructed to guide the engineering development of, planning for, and interpretation of data from a variety of planetary missions: the Kuiper/Pluto Express, Cassini/Huygens, and the Galileo Orbiter/Probe.
Certification of Compliance with Applicable Executive Orders and U.S. Code
By submitting the proposal identified in this Cover Sheet/Proposal Summary in response to this NRA or AO, the Authorizing Official of the proposing institution (or the individual proposer if there is no proposing institution) as identified below:
Willful provision of false information in this proposal and/or its supporting documents, or in reports required under an ensuing award, is a criminal offense (U.S. Code, Title 18, Section 1001).
