Subsurface ice on Mars with rough topography

Aharonson, O.; Schörghofer, N.

doi:10.1029/2005je002636

Cited by 111 publications

(148 citation statements)

References 28 publications

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“…The emission factor (f IR ) has a value of 0.04, and the scattering factor (f scat ) has a value of 0.02. We refer the reader to Aharonson and Schorghofer 64 for additional details on this model. We calculated the temperature of a Martian surface over one solar day during the warmest day of the year (L s 68) at a longitude of 0°and a latitude of 15°S.…”

Section: Methodsmentioning

confidence: 99%

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Cracks in Martian boulders exhibit preferred orientations that point to solar-induced thermal stress

et al. 2015

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The origins of fractures in Martian boulders are unknown. Here, using Mars Exploration Rover 3D data products, we obtain orientation measurements for 1,857 cracks visible in 1,573 rocks along the Spirit traverse and find that Mars rock cracks are oriented in statistically preferred directions similar to those compiled herein for Earth rock cracks found in mid-latitude deserts. We suggest that Martian directional cracking occurs due to the preferential propagation of microfractures favourably oriented with respect to repeating geometries of diurnal peaks in sun-induced thermal stresses. A numerical model modified here with Mars parameters supports this hypothesis both with respect to the overall magnitude of stresses as well as to the times of day at which the stresses peak. These data provide the first direct field and numerical evidence that insolation-related thermal stress potentially plays a principle role in cracking rocks on portions of the Martian surface.

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Section: Methodsmentioning

confidence: 99%

“…Following the example of Aharonson and Schorghofer 64 , we included terms for atmospheric extinction (2), emission (3) and scattering (3) for a flat surface: …”

Section: Methodsmentioning

confidence: 99%

Cracks in Martian boulders exhibit preferred orientations that point to solar-induced thermal stress

et al. 2015

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“…with cosθ = sin ϕ sin δ + cos ϕ cos δ cos h over the full range of h. Finally, to calculate the instantaneous insolation and infrared heating on arbitrary (thermally isolated) slopes, the geometric formulas of Braun and Mitchell (1983) and Aharonson and Schörghofer (2006) are used.…”

Section: A11 Boundary Conditionsmentioning

confidence: 99%

Global Regolith Thermophysical Properties of the Moon From the Diviner Lunar Radiometer Experiment

et al. 2017

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We used infrared data from the Lunar Reconnaissance Orbiter (LRO) Diviner Lunar Radiometer Experiment to globally map thermophysical properties of the Moon's regolith fines layer. Thermal conductivity varies from 7.4 × 10−4 W m−1 K−1 at the surface to 3.4 × 10−3 W m−1 K−1 at depths of ~1 m, given density values of 1,100 kg m−3 at the surface to 1,800 kg m−3 at 1 m depth. On average, the scale height of these profiles is ~7 cm, corresponding to a thermal inertia of 55 ± 2 J m−2 K−1 s−1/2 at 273 K, relevant to the diurnally active near‐surface layer, ~4–7 cm. The temperature dependence of thermal conductivity and heat capacity leads to an ~2 times diurnal variation in thermal inertia at the equator. On global scales, the regolith fines are remarkably uniform, implying rapid homogenization by impact gardening of this layer on timescales <1 Gyr. Regional‐ and local‐scale variations show prominent impact features <1 Gyr old, including higher thermal inertia (> 100 J m−2 K−1 s−1/2) in the interiors and ejecta of Copernican‐aged impact craters and lower thermal inertia (< 50 J m−2 K−1 s−1/2) within the lunar cold spots identified by Bandfield et al. (2014). Observed trends in ejecta thermal inertia provide a potential tool for age dating craters of previously unknown age, complementary to the approach suggested by Ghent et al. (2014). Several anomalous regions are identified in the global 128 pixels per degree maps presented here, including a high‐thermal inertia deposit near the antipode of Tycho crater.

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“…Thermodynamic models of ice stability [e.g., (7)] and equilibration models of various hydrous minerals [e.g., (8,9)] have ruled out some simple explanations for the origin of this water reservoir. Although hydrated sulfates and clay minerals have been detected from orbit, they cover only a small fraction of the entire surface (10)(11)(12) and, to the extent of what can be observed by remote sensing, are limited to bedrock outcrops (13,14), whereas the hydration of the topmost microns of the regolith probed by the Visible and Infrared Mineralogical Mapping Spectrometer (OMEGA) aboard the European Space Agency's Mars Express orbiter is global and usually unrelated to bedrock exposures (6,15).…”

Section: Soil Diversity and Hydration As Observed By Chemcam At Gale mentioning

confidence: 99%

Soil Diversity and Hydration as Observed by ChemCam at Gale Crater, Mars

Meslin

Gasnault

Forni

et al. 2013

Science

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International audienceThe ChemCam instrument, which provides insight into martian soil chemistry at the submillimeter scale, identified two principal soil types along the Curiosity rover traverse: a fine-grained mafic type and a locally derived, coarse-grained felsic type. The mafic soil component is representative of widespread martian soils and is similar in composition to the martian dust. It possesses a ubiquitous hydrogen signature in ChemCam spectra, corresponding to the hydration of the amorphous phases found in the soil by the CheMin instrument. This hydration likely accounts for an important fraction of the global hydration of the surface seen by previous orbital measurements. ChemCam analyses did not reveal any significant exchange of water vapor between the regolith and the atmosphere. These observations provide constraints on the nature of the amorphous phases and their hydration

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Subsurface ice on Mars with rough topography

Cited by 111 publications

References 28 publications

Cracks in Martian boulders exhibit preferred orientations that point to solar-induced thermal stress

Cracks in Martian boulders exhibit preferred orientations that point to solar-induced thermal stress

Global Regolith Thermophysical Properties of the Moon From the Diviner Lunar Radiometer Experiment

Soil Diversity and Hydration as Observed by ChemCam at Gale Crater, Mars

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