PDS: The Planetary Atmospheres Node
Cover Page/Proposal Summary
ROSS-99 NRA 99-OSS-01
Date Due: 5/3/99
|
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: Atmosphere Structures and Particles |
| Major Equipment Proposal? No |
| Do you intend to submit an Education/Public Outreach (E/PO) proposal? No |
| Proposal Title: |
| Theoretical studies of volatile processes in solar system bodies (NAG5-4051) |
| Abbreviated Proposal Title: |
| Volatiles in the outer solar system |
| Principal Investigator: |
| Dr. Jonathan
Lunine Department of Planetary Sciences Lunar & Planetary Lab University of Arizona P.O. Box 210092 1629 E. University Blvd. Tucson, AZ 85721-0092 Phone: 520-621-2789 Fax: 520-626-8250 E-mail: jlunine@lpl.arizona.edu |
| Signature | Date |
| _____________________________________ | ____________ |
| Co-Investigators and Collaborators: | |||
| Type | Name | Affiliation | |
| Sci Co-I | Dr. Alessandro Morbidelli | Obs. de Nice | morby@obs-nice.fr |
| Sci Collab | Dr. Giovanni Valsecchi | CNR-IAS | giovanni@s aturn.ias.rm.cnr.it |
| Sci Collab | Prof. John Eiler | Caltech | eiler@gps.calt ech.edu |
| Sci Collab | Prof. Yuk Yung | Caltech | yly@mercu1.gps. caltech.edu |
Proposal Summary:
Isotopic evidence is used to determine the source regions of the Earth's water budget, as well as the origin and early evolution of volatiles on Saturn's moon Titan. We will track the orbital evolution of icy planetesimals condensed directly at the nebular snowline, primordial comets, and hydrated silicates in the proto-asteroid belt to assess the importance of each of these reservoirs in supplying Earth's oceans. Our work will be constrained by the oceanic deuterium-to-hydrogen ratio, as well as that measured recently in long period comets. We will predict water inventories and D/H for early Mars and Venus. On Titan, models of a massive early Titan atmosphere will be computed to evaluate the interpretation of recent nitrogen and carbon isotopic data. Specifically, the strong fractionation in nitrogen implies loss of a large quantity of nitrogen in atmospheric escape, while the lack of fractionation in the carbon isotopes limits the extent to which methane participated in the escape. Late outgassing of methane as a solution to this dilemma will be examined, as will the plausibility of a massive early nitrogen atmosphere.
