Search Publications
Areas of enhanced ionization in the deep nightside ionosphere of Mars
Gurnett, D. A.; Němec, F.; Morgan, D. D. +1 more
We present observations of areas of enhanced ionization located in the deep nightside ionosphere of Mars as observed by Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) on board the Mars Express spacecraft. Oblique ionospheric echoes coming from the same region observed during several consecutive MARSIS measurements enable us t…
Unique spinel-rich lithology in lunar meteorite ALHA 81005: Origin and possible connection to M3 observations of the farside highlands
Treiman, Allan H.; Gross, Juliane
A new lunar rock type, rich in (Mg, Fe)Al spinel and lacking abundant olivine and pyroxene, was recently detected by near-infrared reflectance spectroscopy by the M3 instrument on the Chandrayaan-1 spacecraft. No such material has been described from lunar rocks, either returned samples or meteorites. Here we describe a fragment of rock…
The nature of lunar volatiles as revealed by Mini-RF observations of the LCROSS impact site
Patterson, G. W.; Neish, C. D.; Bussey, D. B. J. +4 more
On 9 October 2009 the Lunar Crater Observation and Sensing Satellite (LCROSS) impacted Cabeus crater, located near the south pole of the Moon. Prior to that impact, the Mini-RF instruments on ISRO's Chandrayaan-1 and NASA's Lunar Reconnaissance Orbiter (LRO) obtained S band (12.6 cm) synthetic aperture radar images of the impact site at 150 and 30…
Influence of the scar geometry on landslide dynamics and deposits: Application to Martian landslides
Lucas, Antoine; Mège, Daniel; Mangeney, Anne +1 more
Landslides dynamics prediction remains difficult in spite of a considerable number of studies. The runout distance is widely used in analysis of landslide dynamics and in the calibration of the rheological parameters involved in numerical modeling. However, the unknown impact of the significant uncertainty in the shape of the initial released mass…
Observations of thermal tides in the middle atmosphere of Mars by the SPICAM instrument
Montmessin, F.; Bertaux, J. -L.; Withers, Paul +1 more
We use vertical profiles of Martian atmospheric density, pressure, and temperature from the Mars Express SPICAM UV spectrometer to study thermal tides in the poorly studied middle atmosphere region at 70-120 km. Here we show that nonmigrating tides cause zonal pressure variations of tens of percent and zonal temperature variations on the order of …
Modeling radar scattering from icy lunar regoliths at 13 cm and 4 cm wavelengths
Heggy, Essam; Thompson, Thomas W.; Ustinov, Eugene A.
Two orbital synthetic aperture radars (SARs), the Chandrayaan-1 Mini-SAR (13 cm wavelength) and the Lunar Reconnaissance Orbiter (LRO) Mini-RF (13 and 4.2 cm wavelengths), have been imaging the lunar surface searching for ice deposits in the polar permanently shadowed areas. To understand the radar signatures of lunar polar ices, an empirical two-…
Understanding the variability of nightside temperatures, NO UV and O2 IR nightglow emissions in the Venus upper atmosphere
Gérard, J. -C.; Brecht, A. S.; Bougher, S. W. +3 more
Venus Express (VEX) has been monitoring key nightglow emissions and thermal features (O2 IR nightglow, NO UV nightglow, and nightside temperatures) which contribute to a comprehensive understanding of the global dynamics and circulation patterns above ∼90 km. The nightglow emissions serve as effective tracers of Venus' middle and upper …
Interior layered deposits within a perched basin, southern Coprates Chasma, Mars: Evidence for their formation, alteration, and erosion
Hauber, E.; Le Deit, L.; Gwinner, K. +3 more
A basin-like area containing three interior layer deposits (ILDs) on the southern margin of Coprates Chasma was studied. We interpret the area as an ancestral basin and demonstrate that ILD deposition postdates the formation of the current wall rock slopes. The geometry of the ILD and the wall rock spurs form a catchment area between each ILD and …
Goldschmidt crater and the Moon's north polar region: Results from the Moon Mineralogy Mapper (M3)
Clark, R. N.; Head, J. W.; McCord, T. B. +10 more
Soils within the impact crater Goldschmidt have been identified as spectrally distinct from the local highland material. High spatial and spectral resolution data from the Moon Mineralogy Mapper (M3) on the Chandrayaan-1 orbiter are used to examine the character of Goldschmidt crater in detail. Spectral parameters applied to a north pol…
Regional-scale stratigraphy of surface units in Tyrrhena and Iapygia Terrae, Mars: Insights into highland crustal evolution and alteration history
Rogers, A. Deanne; Fergason, Robin L.
The compositional, thermophysical and geologic characteristics of surface units in Iapygia and Tyrrhena Terra (60°E-100°E, 0°-30°S) provide new insights into the compositional stratigraphy of the region. Intercrater plains are dominated by two surface units. The older unit (unit 1) is deficient in olivine and more degraded and likely consists of a…