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Factor analysis and target transformation techniques were applied to the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) spectral dataset to identify spectral endmembers, reduce noise, and automate image analysis. These techniques allow for rapid processing of images and identification of weak spectral signals. We have applied the automated technique to over 3000 CRISM images and successfully...
Dacitic rocks, often indicative of crustal recycling on Earth, have been identified in some regions on Mars, as have possible hydrothermally/aqueously-altered dacites. To enable more robust identification of unaltered and altered dacites on Mars and other planetary bodies, we undertook a spectroscopic-structural-compositional study of altered and unaltered dacites from a dacitic volcanic region in...
Lunar Reconnaissance Orbiter (LRO) Diviner Radiometer, Mini-RF, and LRO Camera data were used to identify and characterize rocky lunar deposits that appear well separated from any potential source crater. Two regions are described: 1) A ∼18,000 km2 area with elevated rock abundance and extensive melt ponds and veneers near the antipode of Tycho crater (167.5°E, 42.5°N). This region has been identified...
The Nili Fossae region of Mars contains some of the most mineralogically diverse bedrock on the planet. Previous studies have established three main stratigraphic units in the region: a phyllosilicate-bearing basement rock, a variably altered olivine-rich basalt, and a capping rock. Here, we present evidence for the localized alteration of the northeast Nili Fossae capping unit, previously considered...
Thermal emission imaging system (THEMIS) and Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) spectral datasets were used to identify high bulk SiO2 and hydrated compositions throughout the Nilosyrtis Mensae region. Four isolated locations were identified across the region showing short wavelength silicate absorptions within the 8–12μm spectral region, indicating surfaces dominated by...
Rock abundance maps derived from the Diviner Lunar Radiometer instrument on the Lunar Reconnaissance Orbiter (LRO) show Tsiolkovskiy crater to have high surface rock abundance and relatively low regolith thickness. The location of the enhanced rock abundance to the southeast of the crater is consistent with a massive, well-preserved impact melt deposit apparent in LRO Miniature Radio Frequency instrument...
A spectral contribution different from that observed for thick dust mantles has been identified in many of the in situ measurements of rocks and regolith acquired by the Miniature Thermal Emission Spectrometer (Mini-TES) instruments on the Mars Exploration Rovers (MER). This spectral contribution is thought to be caused by optically thin surface dust and if not corrected can greatly hinder the mineralogical...
The Mars Global Surveyor (MGS) Thermal Emission Spectrometer (TES) visible/near-infrared and thermal infrared bolometers measured planetary broadband albedo and temperature for more than three Mars years. As seasons progress on Mars, surface temperatures may fall below the frost point of volatiles in the atmosphere (namely, carbon dioxide and water). Systematic mapping of the spatial and temporal...
Spacecraft observations of atmosphereless Solar System bodies, combined with thermophysical modeling, provide important information about the thermal inertia and degree of surface roughness of these bodies. The thermophysical models rely on various methods of generating topography, the most common being the concave spherical segment. We here compare the properties of thermal emission for a number...
We exploit the relative stability and repeatability of the Mars atmosphere at aphelion for an inter-comparison of Mars Global Surveyor/Thermal Emission Spectrometer (MGS/TES) and Mars Reconnaissance Orbiter/Mars Climate Sounder (MRO/MCS) nighttime temperature profiles and aerosol opacity profiles in Mars years 25, 26, 29, 30, and 31. Cross-calibration of these datasets is important, as they together...
Sunlit and shaded slopes have a variety of temperatures based on their orientation with respect to the Sun. Generally, greater slope angles lead to higher anisothermality within the field of view. This anisothermality is detected by measuring changing emitted radiance as a function of viewing angle or by measuring the difference in brightness temperatures with respect to observation wavelength. Thermal...
Systematic temperature mapping and high resolution images reveal a previously unrecognized class of small, fresh lunar craters. These craters are distinguished by near-crater deposits with evidence for lateral, ground-hugging transport. More distal, highly insulating surfaces surround these craters and do not show evidence of either significant deposition of new material or erosion of the substrate...
Near-infrared spectral data indicate the presence of hydrated, poorly crystalline silica where high bulk silica contents have been previously identified in Hellas Basin. No other aqueous phases are identified in these regions and the deposits may be nearly pure. The silica-bearing surfaces are sporadically exposed along a 650km stretch of the western basin rim within a limited elevation range and...
We describe a new retrieval algorithm that accounts for the presence of the systematic background radiance error in the infrared spectra collected by the Mars Global Surveyor (MGS) Thermal Emission Spectrometer (TES). The algorithm is used to retrieve dust and water ice cloud opacities from the nighttime TES nadir spectra. Nighttime dust opacities are systematically higher than the day opacities by...
Mars Climate Sounder (MCS) nadir oriented thermal infrared and solar channel measurements are compared with Thermal Emission Spectrometer (TES) measurements across multiple Mars years. Thermal infrared measurements were compared by convolving the TES data using the MCS spectral band passes. The MCS solar channel measurements were calibrated using Compact Reconnaissance Imaging Spectrometer for Mars...
Hydrated silica is found in a variety of martian deposits within aqueously altered mineral suites. Its common occurrence is attributed to its ease of formation in different weathering environments. Because of its presence in disparate units, hydrated silica makes a good tracer mineral to compare otherwise dissimilar martian deposits and relate their relative degrees of aqueous alteration. This work...
Visible and thermal infrared spacecraft datasets are used to gain insight into the nature of the surface materials and upper martian crust, revealing a distinct transition in the physical properties of martian crustal materials that occurred during the Hesperian era. Contrary to a prevailing view of the martian crust as primarily composed of lava flows, we find that most older regions of Mars have...
Martian equatorial dark regions are dominated by unweathered materials and it has often been assumed that they have not been significantly altered from their source lithology. The suite of minerals present is consistent with a basaltic composition and there has been no need to invoke additional processes to explain the origin of these compositions. We have begun to question this result based on detailed...
Data from the Mars Global Surveyor Thermal Emission Spectrometer (TES) and the Mars Odyssey Thermal Emission Imaging System (THEMIS) instruments are used to assess the mineralogic and dust cover characteristics of landing regions proposed for the Mars Science Laboratory (MSL) mission. Candidate regions examined in this study are Eberswalde crater, Gale crater, Holden crater, Mawrth Vallis, Miyamoto...
Slopes are present in martian apparent surface emissivity observations collected by the Thermal Emission Spectrometer (TES) and the Thermal Emission Imaging System (THEMIS). These slopes are attributed to misrepresenting the surface temperature, either through incorrect assumptions about the maximum emissivity of surface materials or the presumption of a uniform surface temperature within the field...
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