Mathieu Choukroun

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We present new experimental data on the liquidus of ice polymorphs in the H(2)O-NH(3) system under pressure, and use all available data to develop a new thermodynamic model predicting the phase behavior in this system in the ranges (0-2.2 GPa; 175-360 K; 0-33 wt % NH(3)). Liquidus data have been obtained with a cryogenic optical sapphire-anvil cell coupled(More)
Measurements of the carbon and nitrogen isotopic ratios as well as the detection of 40Ar and 36Ar by the gas chromatograph mass spectrometer (GCMS) instrument on board the Huygens probe have provided key constraints on the origin and evolution of Titan's atmosphere, and indirectly on the evolution of its interior. Those data combined with models of Titan's(More)
The state of knowledge about the structure and composition of icy satellite interiors has been significantly extended by combining direct measurements from spacecraft, laboratory experiments, and theoretical modeling. The existence of potentially habitable liquid water reservoirs on icy satellites is dependent on the radiogenic heating of the rock(More)
We propose a thermodynamic model of the properties of liquid water and ices I, III, V, and VI that can be used in the ranges of 0-2200 MPa and 180-360 K. This model is the first to be applicable to all H(2)O phases in these wide ranges, which exceed the stability domain of all phases. Developing empirical or semiempirical expressions for the specific(More)
Introduction. Chemical analyses of rock and rego-lith at the Venera and Vega landing sites [1] suggest that Venus' surface consists of basaltic rocks with variable amounts of S, either as a primary constituent or as a secondary product of atmospheric interactions. Starting with these chemistries, models of Venus mineralogy predict that the surface is(More)
LIBS, AND FLUORESCENCE SPECTROSCOPY J. Blacksberg 1 , Y. Maruyama 3 , M. Choukroun 1 , E. Charbon 3 , G.R.Rossman 2 , 1 Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA 91109, Jordana.blacksberg@jpl.nasa.gov, 2 California Institute of Technology, Division of Geological and Planetary Sciences, Pasadena,(More)
[1] In a series of laboratory experiments, we measure thermal diffusivity, thermal conductivity, and heat capacity of icy regolith created by vapor deposition of water below its triple point and in a low pressure atmosphere. We find that an ice-regolith mixture prepared in this manner, which may be common on Mars, and potentially also present on the Moon,(More)
FLUORESCENCE FOR PLANETARY SURFACE MINERALOGY. J. Blacksberg 1 , Y. Maruyama 3 , M. Choukroun 1 , E. Charbon 3 , G.R.Rossman 2 , 1 Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA 91109, Jordana.blacksberg@jpl.nasa.gov, 2 California Institute of Technology, Division of Geological and Planetary Sciences,(More)
Introduction: The Cassini spacecraft has been orbiting in the Saturn system since July 2004. Remote sensing instruments have discovered dunes, river beds, lakes, seas, impact craters, mountains and cryovolcanic features [e.g. 1 7]. Titan’s activity is somehow similar to that of Earth with methane and ethane playing the role of water and ice that of(More)
Clathrate hydrates, ice-like crystalline compounds in which small guest molecules are enclosed inside cages formed by tetrahedrally hydrogen-bonded water molecules, are naturally abundant on Earth and are generally expected to exist on icy celestial bodies. A prototypical example is Saturn's moon Titan, where dissociation of methane clathrates, a major(More)