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Seidelmann, P. K.; Abalakin, V. K.; Bursa, M.; Davies, M. E.; Bergh, C. de; Lieske, J. H.; Oberst, J.; Simon, J. L.; Standish, E. M.; Stooke, P. J.; Thomas, P. C.

doi:10.1023/a:1013939327465

Cited by 252 publications

(16 citation statements)

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“…where M is mass, C is MOI, a is Mars' equatorial radius (3389.5 km; Seidelmann et al, 2002), ρ(r) is density and r is distance from the center of the planet.…”

Section: Compositional Model Of the Martian Corementioning

confidence: 99%

The composition of Mars

Yoshizaki

McDonough

2020

Geochimica et Cosmochimica Acta

155

154

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Comparing compositional models of the terrestrial planets provides insights into physicochemical processes that produced planet-scale similarities and differences. The widely accepted compositional model for Mars assumes Mn and more refractory elements are in CI chondrite proportions in the planet, including Fe, Mg, and Si, which along with O make up >90% the mass of Mars. However, recent improvements in our understandings on the composition of the solar photosphere and meteorites challenge the use of CI chondrite as an analog of Mars. Here we present an alternative model composition for Mars that avoids such an assumption and is based on data from Martian meteorites and spacecraft observations. Our modeling method was previously applied to predict the Earth's composition. The model establishes the absolute abundances of refractory lithophile elements in the bulk silicate Mars (BSM) at 2.26 times higher than that in CI carbonaceous chondrites. Relative to this chondritic composition, Mars has a systematic depletion in moderately volatile lithophile elements as a function of their condensation temperature. Given this finding, we constrain the abundances of siderophile and chalcophile elements in the bulk Mars and its core. The Martian volatility trend is consistent with ≤7 wt% S in its core, which is significantly lower than that assumed in most core models (i.e., >10 wt% S). Occurrence of ringwoodite at the Martian core-mantle boundary might have contributed to the partitioning of O and H into the Martian core.

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“…where M is mass, C is MOI, a is Mars' equatorial radius (3389.5 km; Seidelmann et al, 2002), ρ(r) is density and r is distance from the center of the planet.…”

Section: Compositional Model Of the Martian Corementioning

confidence: 99%

The composition of Mars

Yoshizaki

McDonough

2020

Geochimica et Cosmochimica Acta

155

154

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“…Interannual variability below the thermosphere ( 100 km) is accounted for by various suspended dust scenarios. The MCD's postprocessing software was used to combine the low-resolution MCD surface pressure data (3.75 ı 5.625 ı latitude/longitude) with high-resolution (32 pixels/degree) Mars Global Surveyor (MGS) MOLA topology and Viking Lander 1 pressure records to reconstruct surface pressure at high-resolution [Lemoine et al, 2001;Seidelmann et al, 2002;Spiga et al, 2007].…”

Section: Martian Atmospherementioning

confidence: 99%

Influence of dust loading on atmospheric ionizing radiation on Mars

2014

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Measuring the radiation environment at the surface of Mars is the primary goal of the Radiation Assessment Detector on the NASA Mars Science Laboratory's Curiosity rover. One of the conditions that Curiosity will likely encounter is a dust storm. The objective of this paper is to compute the cosmic ray ionization in different conditions, including dust storms, as these various conditions are likely to be encountered by Curiosity at some point. In the present work, the Nowcast of Atmospheric Ionizing Radiation for Aviation Safety model, recently modified for Mars, was used along with the Badhwar & O'Neill 2010 galactic cosmic ray model. In addition to galactic cosmic rays, five different solar energetic particle event spectra were considered. For all input radiation environments, radiation dose throughout the atmosphere and at the surface was investigated as a function of atmospheric dust loading. It is demonstrated that for galactic cosmic rays, the ionization depends strongly on the atmosphere profile. Moreover, it is shown that solar energetic particle events strongly increase the ionization throughout the atmosphere, including ground level, and can account for the radio blackout conditions observed by the Mars Advanced Radar for Subsurface and Ionospheric Sounding instrument on the Mars Express spacecraft. These results demonstrate that the cosmic rays' influence on the Martian surface chemistry is strongly dependent on solar and atmospheric conditions that should be taken into account for future studies.

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“…[7] The altimetry measured by MOLA during the Mars Global Surveyor mission allows us to study the geometry of valleys at a spatial resolution of $500 m with a height accuracy of $1 m [Smith, 1998;. For the studied regions, MOLA altimetry was projected onto the Martian ellipsoid with an equatorial axis of 3396.19 km and a polar axis of 3376.20 km, defined by the International Astronomical Union as the Mars IAU 2000 [Seidelmann et al, 2002], with a sinusoidal projection centered at a given meridian. The geographic coordinates follow the Martian standard coordinate system with planetocentric latitudes and east longitudes [Duxbury et al, 2002].…”

Section: Mola Altimetrymentioning

confidence: 99%

“…Using the photogrammetric software developed both at the Deutsches Zentrum für Luft-and Raumfahrt (DLR) and the Technical University of Berlin [Scholten et al, 2005], we projected level 2 images onto a reference surface corresponding to the MOLA topography with a spatial grid of 5 km pixel -1 Neuman et al, 2003], a sinusoidal projection at a given central meridian, and the best spatial resolution, taking into account the spacecraft position, the camera orientation along the ground track and the camera characteristics included in exterior orientation data (Figure 1b). The coordinates of ortho-rectified nadir images are defined in the planetocentric system of the Mars IAU 2000 ellipsoid [Seidelmann et al, 2002, Duxbury et al, 2002.…”

Section: Hrsc Imagesmentioning

confidence: 99%

“…The location of each 3-D object point is defined with its accuracy in three dimensions (sx, sy, and sz) [Scholten et al, 2005;Albertz et al, 2005]. At this step, we remove all 3-D object points that are imprecisely located, e.g., sx, sy and sz must be <100 m. The fourth step is the transformation of Cartesian coordinates of 3-D object points in geographic latitude, longitude, and height projected on the MARS IAU ellipsoid [Duxbury et al, 2002;Seidelmann et al, 2002] (Figure 1d). The height is calculated taking into account the Martian geoid defined as the topographic reference for the Martian heights, i.e., the areoid .…”

Section: Hrsc Digital Elevation Modelmentioning

confidence: 99%

See 1 more Smart Citation

Topography of valley networks on Mars from Mars Express High Resolution Stereo Camera digital elevation models

Ansan¹,

Mangold²,

Masson³

et al. 2008

J. Geophys. Res.

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[1] Martian valley networks have been identified mainly in the Noachian heavily cratered uplands. The geometry of valley networks can be studied using Mars Orbiter Laser Altimeter (MOLA) altimetry, which is sufficient to map large valleys without a detailed 3-D shape of valley networks. Imaging from the Mars Express High Resolution Stereo Camera (HRSC) is used to generate digital elevation models (DEMs) with resolution 50 m and vertical accuracy <60 m. We studied valleys near Huygens crater and in the Aeolis region both in the Noachian bedrock and on the West Echus plateau in Hesperian bedrock. HRSC DEMs in these areas show that (1) drainage density is 3 times higher than is observed in MOLA data, (2) degree of ramification is 1 order more than with MOLA, (3) transverse valley profiles show a V shape more accurately and a minimum depth of $20 m, and (4) higher drainage density shows greater headward extension that is not correlated to greater valley depth. The deepest valleys (400 m) are found in the Huygens region, where the density in the DEM is 0.1 km À1 , compared to shallow valleys (<100 m) of the Echus region, where the density is higher ($0.3 km À1 ). These regional differences are due to spatially variable preservation and bedrock lithology. Longitudinal profiles suggest variations in duration of activity: profile concavity is only developed in some Noachian terrains. Valleys visible in HRSC images correspond to topographic features in DEMs showing the same geometry as terrestrial valleys thought to be formed by overland flows and seepage.

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Cited by 252 publications

References 0 publications

The composition of Mars

The composition of Mars

Influence of dust loading on atmospheric ionizing radiation on Mars

Topography of valley networks on Mars from Mars Express High Resolution Stereo Camera digital elevation models

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