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Project Reports

• Task 3.4.2 Tholin Analysis Based on Selective Detection of Functional Groups

  Titan organics comprise a very complex mixture of compounds. Several approaches are being developed that provide targeted detection of specific functional groups, such as nitriles, imines, primary amines, and carbon-carbon multiple bonds.

  ROADMAP OBJECTIVES: 1.1 2.2 3.1

• Task 3.3.2 Precipitation of Organics in Titan Lakes

  Preliminary evaporation-precipitation experiments have been conducted on benzene and acetylene in liquid ethane within the cryostat to simulate processes on Titan lake shores.

  ROADMAP OBJECTIVES: 1.1 2.2 3.1

• Task 2.1.2.1 Atmospheric State and Dynamics

  The chemical model requires a description of the background state of the atmosphere, specifically temperature and circulation as a function of latitude and longitude.

  ROADMAP OBJECTIVES: 1.1 2.2 3.1

• Task 1.2 Interaction of Methane/ethane With Water Ice

  Laboratory work led to several results. Tholins are entrained in the subsurface during a methane rain. As the liquid evaporates, the tholins remain trapped in the subsurface. The JPL Titan chamber (Figure 1) also was used to test a rain drop sensor developed by a group of students at University of Idaho that could be embarked on future missions to Titan.

  ROADMAP OBJECTIVES: 1.1 2.2 3.1

• Task 3.5.1 Titan Genetics

  An open question is: “What chemical structures might support the genetic component of Darwinian evolution in Titan environments?” This is being approached theoretically and experimentally.

  ROADMAP OBJECTIVES: 1.1 3.1 3.2

• Task 3.4.1 Tholin Chemical Analysis Using Nuclear Magnetic Resonance

  The definition and assessment of future flight capable analytical methods for complex organic analysis was pursued, in particular evaluating the potential of nuclear magnetic resonance (NMR).

  ROADMAP OBJECTIVES: 1.1 2.2 3.1

• Task 3.5.2 Energetics of Titan Life

  Thermochemical and dynamic modeling is being used to provide improved constraints on the available chemical energy and trace element fluxes to facilitate potential life on the surface of Titan.

  ROADMAP OBJECTIVES: 1.1 2.2 3.1

• Task 3.3.1 Solubility of Gases and Organics in Liquid Methane and Ethane

  The solubilities of gases and organics in liquid ethane and methane have been measured.

  ROADMAP OBJECTIVES: 1.1 2.2 3.1

• Task 3.1.1 Reactions of Organics With Ices and Mineral Grains

  A goal is to determine the potential role of mineral surfaces (i.e. meteorite fragments) in catalyzing reactions on Titan’s surface. There is also the possibility of low-energy electron and visible/UV photon stimulated chemistry on aggregates and organic aerosol surfaces.

  ROADMAP OBJECTIVES: 1.1 2.2 3.1

• Task 3.1.2 Chemistry Active in Titan Dunes

  Triboelectric reactions of complex organics and water ice are a potential chemical mechanism active in the dunes of Titan. Laboratory experiments have been conducted to simulate and assess how important this possibility can be in the Titan context.

  ROADMAP OBJECTIVES: 1.1 2.2 3.1

• Task 2.1.2.2 Atmospheric Observations

  A previously unsuspected seasonal change in the altitude of Titan’s detached haze layer was discovered and used to test current models of the formation of the haze and related dynamical and microphysical processes.

  ROADMAP OBJECTIVES: 1.1 2.2 3.1

• Task 2.2.1 Characterization of Aerosol Nucleation and Growth

  A quantitative understanding of the particle formation and growth in the Titan atmosphere is still unrealized. Laboratory work is being conducted to clarify these processes.

  ROADMAP OBJECTIVES: 1.1 2.2 3.1

• Task 2.2.2 Ultraviolet/infrared Spectroscopy and Photoprocessing of Ice Films

  Only near-ultraviolet light at long wavelengths can penetrate to the deep Titan atmosphere, not being absorbed by atmospheric gas-phase species. Large hydrocarbons can absorb at these longer wavelengths. Condensed onto atmospheric particles, such hydrocarbons can undergo photochemical reactions initiated by absorption of near-ultraviolet photons.

  ROADMAP OBJECTIVES: 1.1 2.2 3.1

• Task 2.1.1 Master Atmospheric Chemistry Simulation

  The development of a master atmospheric model is nearing completion. Based on an older Titan model, the current model has been updated this year to include a treatment of chemical equilibrium, a description of aerosols, and a numerical model for condensation on and sublimation of atmospheric organic molecules from aerosol particles. To allow a global simulation of Titan atmospheric organic chemistry, the computer model is being recoded to support parallel processing.

  ROADMAP OBJECTIVES: 1.1 2.2 3.1

• Task 1.1.2 Models of the Reaction Between Hydrocarbons and Water Ice

  Reactions between hydrocarbons and water ice was modeled to assess the possible extent of prebiotic compound formation in this context. Various environments where organics and liquids could be in contact were considered.

  ROADMAP OBJECTIVES: 1.1 2.2 3.1 3.2 3.3

• Task 1.1.1 Models of the Internal Dynamics: Formation of Liquids in the Subsurface and Relationships With Cryovolcanism

  The internal and external geologic evolution of Titan was investigated so as to constrain the environment in which organic evolution has proceeded over time.

  ROADMAP OBJECTIVES: 1.1 2.2 3.1 3.2 3.3

• Task 3.3.3 Solubility in Lakes

  Atomistic simulations are being used to study the chemical environment of Titan’s hydrocarbon lakes.

  ROADMAP OBJECTIVES: 1.1 2.2 3.1