Search Publications
Galileo dust data from the jovian system: 2000 to 2003
Krüger, H.; Srama, R.; Hamilton, D. P. +17 more
The Galileo spacecraft was the first man-made satellite of Jupiter, orbiting the planet between December 1995 and September 2003. The spacecraft was equipped with a highly sensitive dust detector that monitored the jovian dust environment between approximately 2 and 370 RJ (jovian radius RJ=71 492 km). The Galileo dust detect…
The light curve of asteroid 2867 Steins measured by VIRTIS-M during the Rosetta fly-by
Mottola, S.; Barucci, M. A.; Erard, S. +11 more
On 5 September 2008, the Rosetta spacecraft encountered the asteroid 2867 Steins on its way to the comet 67P/Churyumov-Gerasimenko. This was the first of two planned asteroid fly-bys performed by the probe, the second fly-by being with the much larger asteroid 21 Lutetia in July 2010. The VIRTIS imaging spectrometer (IFOV 0.250 mrad, overall spect…
Optical properties of aerosols in Titan’s atmosphere: Large fluffy aggregates
Keller, H. U.; Rodin, A. V.; Skorov, Yu. V.
Scattering properties of large ( N>2000) aggregates of monomers as found in Titan's atmosphere during the descent of the Cassini/Huygens probe are numerically calculated. We extend our previous quantitative analysis of small aggregates ( N≤256) to verify the obtained conclusions. To calculate the light scattering of such big non-spherical aggre…
Evidence for surface variegation in Rosetta OSIRIS images of asteroid 2867 Šteins
Sierks, H.; Keller, H. U.; Hviid, S. F. +4 more
The OSIRIS camera onboard Rosetta successfully acquired images of asteroid 2867 Steins through a variety of color filters during the flyby on 5 September 2008. The best images of this 5 km diameter asteroid have a resolution of 78 m per pixel. We process the images by deconvolving with the point spread function and enlarging through the Mitchell-N…
Attitude and angular rates of planetary probes during atmospheric descent: Implications for imaging
Lorenz, Ralph D.
Attitude dynamics data from planetary missions are reviewed to obtain a zeroth-order expectation on the tilts and angular rates to be expected on atmospheric probes during descent: these rates are a strong driver on descent imager design. While recent Mars missions have been equipped with capable inertial measurements, attitude measurements for mi…
A new approach for estimating Titan's electron conductivity based on data from relaxation probe sensors on the Huygens experiment
Rodrigo, R.; Fulchignoni, M.; Ferri, F. +15 more
The Huygens Probe measured the electrical conductivity of Titan atmosphere from about 140 km down to the surface, employing relaxation and mutual impedance techniques. Previous analyses have shown some differences on the conductivity measurements obtained with two independent sensors - relaxation probe (RP) and mutual impedance probe (MIP). A 20-f…
Analysis of disturbances in the Planetary Fourier Spectrometer through numerical modeling
Saggin, Bortolino; Comolli, Lorenzo
Fourier transform spectrometers are instruments with high sensitivity to many kinds of disturbances. This study started from the analysis of the disturbances related to mechanical vibrations on the PFS FTIR spectrometer to show how the measured spectra can differ from the actual ones. The complete study, more in general, accounts for the character…
Analysis of two sections of Shalbatana Vallis’ tributary channels
Kereszturi, Akos
Six tributaries of Shalbatana outflow channel were analyzed based on visible imagery by THEMIS, MOC, HRSC, and HiRISE, as well as on topographic data by MOLA. Two different sections could be identified on the tributaries: the upper and the lower reaches. The upper reaches are shallow, showing U-shaped cross-sectional profiles. Their bottom level i…
Reconstruction of nonmonotonic electron density profiles of the Martian topside ionosphere
Wang, X. -D.; Zou, H.; Wang, J. -S. +1 more
One of the problems in reconstructing the real ionosphere from an ionogram is the occurrence of a 'valley,' where electron density decreases with altitude and make a non-monotonic profile. For the case of the Earth ionosphere, the ordinary and extraordinary ray data, accompanied with an empirical model, based on the observations, are necessary to …
Trajectory and atmospheric structure from entry probes: Demonstration of a real-time reconstruction technique using a simple direct-to-Earth radio link
Withers, Paul
The reconstruction of the trajectory and atmospheric structure associated with an entry probe has traditionally relied upon onboard accelerometer measurements. Here we outline an equivalent reconstruction technique that uses Doppler-shifted direct-to-Earth transmissions instead. A critical assumption is that the entry probe's angle of attack is ze…