Search Publications
Remote sensing of a comet at millimeter and submillimeter wavelengths from an orbiting spacecraft
Hartogh, Paul; Lellouch, Emmanuel; Rauer, Heike +19 more
The ESA Rosetta Spacecraft, launched on March 2, 2004 with the ultimate destination being Comet 67P/Churyumov-Gerasimenko, carries a relatively small and lightweight millimeter-submillimeter spectrometer instrument, the first of its kind launched into deep space. The instrument, named Microwave Instrument for the Rosetta Orbiter (MIRO), consists o…
Tracking the edge of the south seasonal polar cap of Mars
Grassi, D.; Formisano, V.; Giuranna, M. +1 more
The advance and retreat of the polar caps were one of the first observations that indicated Mars had seasons. Because a large portion of the atmosphere is cycled in and out of the seasonal caps during the year, the frost deposits play a significant role in regional and global atmospheric circulation. Understanding the nature of the seasonal polar …
Electromagnetic measurements on Martian soil analogs: Implications for MARSIS and SHARAD radars in detecting subsoil water
Pettinelli, Elena; Vannaroni, Giuliano; Cereti, Annamaria +1 more
In this work a laboratory investigation on the electrical and magnetic properties of magnetite-bearing and water-bearing granular mixtures, selected as Martian soil simulants, is presented. The objective of these measurements is the estimation of the performance of space-borne ground penetrating radars for detection of subsurface water (both solid…
Huygens Probe descent dynamics inferred from Channel B signal level measurements
Plettemeier, D.; Bird, M. K.; Edenhofer, P. +3 more
The signal strength of the Huygens Probe Channel B transmission to the Cassini Orbiter was monitored during the Probe descent through Titan's atmosphere on 14 January 2005. A model of the Probe motion during the mission was constructed to include Probe spin, coning motion and tilt caused by varying wind speeds. This simple model is sufficient to r…
Mode identification of terrestrial ULF waves observed by Cluster: A case study
Nilsson, H.; Walker, S. N.; Dunlop, M. +4 more
Using multipoint measurements from the Cluster mission wave identification techniques are applied to observations of ULF waves made in the terrestrial foreshock with the aim of identifying the modes and properties of the waves taking into account the effects of a high beta plasma. The wave properties in the spacecraft and plasma rest frames are ex…
Comparison of the dust distributions in the innermost comae of comets—1P/Halley and 19P/Borrelly spacecraft observations
Thomas, Nicolas; Tenishev, Valeriy; Combi, Michael +3 more
We present a comparative study of the inner comae of comets 1P/Halley and 19P/Borrelly using data from the Halley Multicolour Camera (HMC) onboard Giotto and the Miniature Integrated Camera and Spectrometer onboard Deep Space 1 (DS1). We show that the dust brightness dependence as a function of radial distance is different for both comets. We sugg…
Radiative transfer in layered media: Application to the radar sounding of Martian polar ices. II
Ilyushin, Ya. A.
The paper addresses the problem of the retrieval of the physical parameters of the Martian polar ices from the ground-penetrating radar (GPR) measurements. The results of the previous paper [Ilyushin, Y.A., Seu, R., Phillips, R.J., 2005. Subsurface radar sounding of the Martian polar cap: radiative transfer approach. Planet. Space Sci. 53(14-15), …
Titan atmosphere profiles from Huygens engineering (temperature and acceleration) sensors
Lorenz, Ralph D.
Data from several Huygens probe housekeeping sensors (an engineering accelerometer and housekeeping temperature sensors) are studied to determine how effectively such nonideal instruments may characterize the density or temperature structure of the atmosphere. While only confirming the results of the dedicated atmospheric structure instrument, thi…
The Huygens Probe Descent Trajectory Working Group: Organizational framework, goals, and implementation
Lebreton, Jean-Pierre; Witasse, Olivier; Matson, Dennis L. +3 more
Cassini/Huygens, a flagship mission to explore the rings, atmosphere, magnetic field, and moons that make up the Saturn system, is a joint endeavor of the National Aeronautics and Space Administration, the European Space Agency, and Agenzia Spaziale Italiana. Comprising two spacecraft - a Saturn orbiter built by NASA and a Titan entry/descent prob…
Statistical properties of small-amplitude Langmuir waves in the Earth's electron foreshock
Soucek, J.; Décréau, P.; Krasnoselskikh, V. V. +2 more
We present the results of a statistical study of Langmuir waves observed by the Cluster spacecraft in the Earth's electron foreshock. To classify the probability density distributions of the logarithms of the wave energies, a Pearson technique is used. We show that experimental distributions can be better approximated, in a statistical sense, by B…