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Arvidson, R.

Publications and source records attributed to Arvidson, R..

At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2020

The Stratigraphy of Central and Western Butte and the Greenheugh Pediment Contact

The Greenheugh pediment at the base of Aeolis Mons (Mt. Sharp), which may truncate units in the Murray formation and is capped by a thin sandstone unit, appears to represent a major shift in climate history within Gale crater. The pediment appears to be an erosional remnant of potentially a much more extensive feature. Curiosity’s traverse through the southern extent of Glen Torridon (south of Vera Rubin ridge) has brought the rover in contact with several new stratigraphic units that lie beneath the pediment. These strata were visited at two outcrop-forming buttes (Central and Western butte- both remnants of the retreating pediment) south of an orbitally defined boundary marking the transition from the Fractured Clay-bearing Unit (fCU) and the fractured Intermediate Unit (fIU). Here we present preliminary interpretations of the stratigraphy within Central and Western buttes and propose the Western butte cap rocks do not match the pediment capping unit.

Bryk, A. B.↗
NASA NTRS2014

In Situ Radiometric and Exposure Age Dating of the Martian Surface

We determined radiogenic and cosmogenic noble gases in a mudstone on the floor of Gale Crater. A K-Ar age of 4.21 +/- 0.35 billion years represents a mixture of detrital and authigenic components and confirms the expected antiquity of rocks comprising the crater rim. Cosmic-ray-produced 3He, 21Ne, and 36Ar yield concordant surface exposure ages of 78 T 30 million years. Surface exposure occurred mainly in the present geomorphic setting rather than during primary erosion and transport. Our observations are consistent with mudstone deposition shortly after the Gale impact or possibly in a later event of rapid erosion and deposition. The mudstone remained buried until recent exposure by wind-driven scarp retreat. Sedimentary rocks exposed by this mechanism may thus offer the best potential for organic biomarker preservation against destruction by cosmic radiation.

age dating↗
NASA NTRS2013

A Habitable Fluvio-Lacustrine Environment at Yellowknife Bay, Gale Crater, Mars

The Curiosity rover discovered fine-grained sedimentary rocks, which are inferred to represent an ancient lake and preserve evidence of an environment that would have been suited to support a martian biosphere founded on chemolithoautotrophy. This aqueous environment was characterized by neutral pH, low salinity, and variable redox states of both iron and sulfur species. Carbon, hydrogen, oxygen, sulfur, nitrogen, and phosphorus were measured directly as key biogenic elements; by inference, phosphorus is assumed to have been available. The environment probably had a minimum duration of hundreds to tens of thousands of years. These results highlight the biological viability of fluvial-lacustrine environments in the post-Noachian history of Mars.

Mars↗
NASA NTRS2013

Smectites on Cape York, Matijevic Hill, Mars, Observed and Characterized by Crism and Opportunity

Opportunity has conducted an extensive "walk-about" and set of in-situ measurements on strata exposed on the inboard side of Cape York, a segment of the dissected rim of the Noachian-age approx.22 km wide Endeavour crater [1] (Fig. 1). The specific region for the observations (Matijevic Hill) was chosen based on along track oversampled (ATO) CRISM hyperspectral observations (processed to 5 m/pixel) that showed the presence of exposures of Fe/Mg smectite phyllosilicates. We describe the first ground-based observations of phyllosilicates on Mars and discuss implications based on the combined CRISM and Opportunity measurements.

Arvidson, R.↗
NASA NTRS2010

Beijing Lunar Declaration 2010: B) Technology and Resources; Infrastructures and Human Aspects; Moon, Space and Society

We report on the Beijing Lunar Declaration endorsed by the delegates of the Global Lunar Conference/11th ILEWG Conference on Exploration and Utilisation of the Moon, held at Beijing on 30 May- 3 June 2010. Specifically we focus on Part B:Technologies and resources; Infrastructures and human aspects; Moon, Space, Society and Young Explorers. We recommend continued and enhanced development and implementation of sessions about lunar exploration, manned and robotic, at key scientific and engineering meetings. A number of robotic missions to the Moon are now undertaken independently by various nations, with a degree of exchange of information and coordination. That should increase towards real cooperation, still allowing areas of competition for keeping the process active, cost-effective and faster. - Lunar landers, pressurized lunar rover projects as presented from Europe, Asia and America are important steps that can create opportunities for international collaboration, within a coordinated village of robotic precursors and assistants to crew missions. - We have to think about development, modernization of existing navigation capabilities, and provision of lunar positioning, navigation and data relay assets to support future robotic and human exploration. New concepts and new methods for transportation have attracted much attention and are of great potential.

Arvidson, R.↗
NASA NTRS2007

Clay Bearing Units in the Region around Mawrth Vallis: Stratigraphy, Extent, and Possible Alteration Fronts

The largest exposure of phyllosilicates on Mars occurs on the highland plains around Mawrth Vallis. This exposure extends for about 300 km southward from the edge of the dichotomy boundary, covering an area greater than 200 x 300 kilometers over an elevation range of approximately 2000 meters. At least two different types of hydrated phyllosilicates (Fe/Mg-rich and Al-rich phyllosilicates) have been identified in OMEGA data based on absorption bands near 2.3 and 2.2 micrometers, respectively. These clay-bearing units are associated with layered, indurated light-toned units with complex spatial and stratigraphic relationships, and are unconfomably overlain by a darker, indurated, more heavily cratered unit. Ongoing analysis of OMEGA (approximately 1 kilometer/pixel) and CRISM multi-spectral (MSP, 200 meters/pixel) data reveal hydrated minerals with absorptions at approximately 2.2 or 2.3 micrometers in locations up to 300 kilometers away from the borders of the previously identified extent of clay-bearing units. We seek to: 1) further constrain the mineralogy of the hydrated species identified in [5], and 2) understand spatial and stratigraphic relationships between the different hydrated minerals and the cratered plains units in which they are found. In this work we perform mineralogical and stratigraphic comparisons between units to test whether these extended units may be related, in order to establish a broad zone of alteration.

Dobrea, E. Z. Noe↗
NASA NTRS2006

ROCK AND SOIL PHYSICAL PROPERTIES AT THE MER GUSEV CRATER AND MERIDIANI PLANUM LANDING SITES

Following the successful landings of both Mars Exploration Rover (MER) vehicles at Gusev Crater and Meridiani Planum, respectively, their Athena suite of instruments is being used to study the geologic history of these two very different landing sites on Mars that had been selected on the basis of showing different types of evidence for aqueous processes in the planet s past. Utilizing the on-board instruments as well as the rovers mobility system, a wide range of physical properties investigations is carried out as well - the subject of this abstract - that provide additional information on the geology and processes at the sites. Results of the mission in general as well as of the physical properties studies thus far greatly exceed expectations in that observations and measurements by both vehicles show a rich variety in materials and processes: the Gusev site in the vicinity of the lander is remarkably flat and generally devoid of large rocks along traverses up to the time of this writing (approx.Sol 50) and suggestive of a deflated surface with generally only thin veneers of bright dust while exhibiting evidence of a widespread occurrence of a crust from cemented fines that has been observed to fail in the form of blocky clods when disturbed by vehicle rolling action; numerous small and shallow depressions - presumably created by impacts - are observed at the site which are infilled with bright, fine-grained material that likewise appears indurated and which was studied by a trenching experiment; small ripple bedforms are scattered across the site and were characterized in terms of particle size distributions. At the Meridiani site, studies so far - up to approx.Sol 33 - have focussed on soils and the rock outcrop encountered within the approx.20 m diameter crater that the spacecraft came to rest in: from a physical properties point of view, a mantle of dark, well-sorted, apparently basaltic sand with small to moderate cohesion has been of interest - and has been studied by a trenching experiment - as well as a fine-grained unit underlying the mantle at least locally within the crater. Rock grindings were accomplished successfully at both sites at the time of this writing, suggesting different strengths of the two targets (the basaltic rock nicknamed Adirondack at Gusev and the Meridiani rock outcrop) in addition to enabling compositional measurements below the original rock surfaces.

Ming, Douglas W.↗
NASA NTRS2005

Overview of Athena Microscopic Imager Results

The Athena science payload on the Mars Exploration Rovers (MER) includes the Microscopic Imager (MI). The MI is a fixed-focus camera mounted on an extendable arm, the Instrument Deployment Device (IDD). The MI acquires images at a spatial resolution of 31 microns/pixel over a broad spectral range (400 - 700 nm). The MI uses the same electronics design as the other MER cameras but its optics yield a field of view of 32 32 mm across a 1024 1024 pixel CCD image. The MI acquires images using only solar or skylight illumination of the target surface. The MI science objectives, instrument design and calibration, operation, and data processing were described by Herkenhoff et al. Initial results of the MI experiment on both MER rovers (Spirit and Opportunity) have been published previously. Highlights of these and more recent results are described.

Herkenhoff, K.↗
NASA NTRS2005

Sulfate Deposition in Regolith Exposed in Trenches on the Plains Between the Spirit Landing Site and Columbia Hills in Gusev Crater, Mars

During its exploration within Gusev crater between sol 01 and sol 158, the Spirit rover dug three trenches (Fig. 1) to expose the subsurface regolith [1, 2, 9]. Laguna trench (approx. 6 cm deep, approx.203 m from the rim of Bonneville crater) was dug in Laguna Hollow at the boundary of the impact ejecta from Bonneville crater and the surrounding plains. The Big Hole trench (approx. 6-7 cm deep) and The Boroughs trench (approx. 11 cm deep) were dug in the plains between the Bonneville crater and the Columbia Hills (approx.556 m and approx.1698 m from the rim of Bonneville crater respectively). The top, wall and floor regolith of the three trenches were investigated using the entire set of Athena scientific instruments [10].

Wang, Alian↗
NASA NTRS2004

Superficial Deposits at Gusev Crater Along Spirit Rover Traverses

The Mars Exploration Rover Spirit has traversed a fairly flat, rock-strewn terrain whose surface is shaped primarily by impact events, although some of the landscape has been altered by eolian processes.Impacts ejected basaltic rocks that probably were part of locally formed lava flows from at least 10 meters depth.Some rocks have been textured and/or partially buried by windblown sediments less than 2 millimeters in diameter that concentrate within shallow, partially filled, circular impact depressions referred to as hollows.The terrain traversed during the 90-sol (martian solar day) nominal mission shows no evidence for an ancient lake in Gusev crater.

Grant, J. A.↗
NASA NTRS2004

Coordinated Observations of Aeolian Features from the Mars Exploration Rovers (MER) and the Mars Express High Resolution Stereo Camera and Other Orbiters

Surface features associated with aeolian (wind) processes at the Mars Exploration Rover (MER) landing sites for Spirit (Gusev crater) and Opportunity (Sinus Meridiani) were observed from the surface and from orbit through coordinated observations by the rovers and the Mars Express orbiter High Resolution Stereo Camera and compared with features seen in other orbiter data and with wind vectors predicted by a numerical mesoscale model of the atmosphere.

Greeley, R.↗
NASA NTRS2004

MER Field Geologic Traverse in Gusev Crater, Mars: Initial Results From the Perspective of Spirit

This report casts the initial results of the traverse and science investigations by the Mars Exploration Rover (MER) Spirit at Gusev crater [1] in terms of data sets commonly used in field geologic investigations: Local mapping of geologic features, analyses of selected samples, and their location within the local map, and the regional context of the field traverse in terms of the larger geologic and physiographic region. These elements of the field method are represented in the MER characterization of the Gusev traverse by perspective-based geologic/morphologic maps, the placement of the results from Mossbauer, APXS, Microscopic Imager, Mini-TES and Pancam multispectral studies in context within this geologic/ morphologic map, and the placement of the overall traverse in the context of narrow-angle MOC (Mars Orbiter Camera) and descent images. A major campaign over a significance fraction of the mission will be the first robotic traverse of the ejecta from a Martian impact crater along an approximate radial from the crater center. The Mars Exploration Rovers have been conceptually described as 'robotic field geologists', that is, a suite of instruments with mobility that enables far-field traverses to multiple sites located within a regional map/image base at which in situ analyses may be done. Initial results from MER, where the field geologic method has been used throughout the initial course of the investigation, confirm that this field geologic model is applicable for remote planetary surface exploration. The field geologic method makes use of near-field geologic characteristics ('outcrops') to develop an understanding of the larger geologic context through continuous loop of rational steps focused on real-time hypothesis identification and testing. This poster equates 'outcrops' with the locations of in situ investigations and 'regional context' with the geology over distance of several kilometers. Using this fundamental field geologic method, we have identified the basic local geologic materials on the floor of Gusev at this site, their compositions and likely lithologies, origins, processes that have modified these materials, and their potential significance in the interpretation of the regional geology both spatially and temporally.

Crumpler, L.↗
NASA NTRS2004

First Results of the Athena Microscopic Imager Investigation

The Athena science payload on the Mars Exploration Rovers (MER) includes the Microscopic Imager (MI). The MI is a fixed-focus camera mounted on an extendable arm, the Instrument Deployment Device (IDD). The MI acquires images at a spatial resolution of 30 microns/pixel over a broad spectral range (400 - 700 nm). The MI uses the same electronics design as the other MER cameras but its optics yield a field of view of 31 x 31 mm across a 1024 x 1024 pixel CCD image. The MI acquires images using only solar or skylight illumination of the target surface. A contact sensor is used to place the MI slightly closer to the target surface than its best focus distance (about 69 mm), allowing concave surfaces to be imaged in good focus. Coarse focusing (approx. 2 mm precision) is achieved by moving the IDD away from a rock target after contact is sensed. The MI optics are protected from the Martian environment by a retractable dust cover. This cover includes a Kapton window that is tinted orange to restrict the spectral bandpass to 500 - 700 nm, allowing crude color information to be obtained by acquiring images with the cover open and closed. The MI science objectives, instrument design and calibration, operation, and data processing were described by Herkenhoff et al. Initial results of the MI experiment on both MER rovers ('Spirit' and 'Opportunity') are described below.

Herkenhoff, K.↗
NASA NTRS2004

Preliminary Assessment of Mars Exploration Rover Landing Site Predictions

Selection of the Mars Exploration Rover (MER) landing sites took place over a three year period in which engineering constraints were identified, 155 possible sites were downselected to the final two, surface environments and safety considerations were developed, and the potential science return at the sites was considered. Landing sites in Gusev crater and Meridiani Planum were selected because they appeared acceptably safe for MER landing and roving and had strong morphologic and mineralogical indicators of liquid water in their past and thus appeared capable of addressing the science objectives of the MER missions, which are to determine the aqueous, climatic, and geologic history of sites on Mars where conditions may have been favorable to the preservation of evidence of possible pre-biotic or biotic processes. Engineering constraints important to the selection included: latitude (10 N-15 S) for maximum solar power; elevation (<-1.3 km) for sufficient atmosphere to slow the lander; low horizontal winds, shear and turbulence in the last few kilometers to minimize horizontal velocity; low 10-m scale slopes to reduce airbag spinup and bounce; moderate rock abundance to reduce abrasion or stroke-out of the airbags; and a radar-reflective, load-bearing and trafficable surface safe for landing and roving that is not dominated by fine-grained dust. In selecting the MER landing sites these engineering constraints were addressed via comprehensive evaluation of surface and atmospheric characteristics from existing remote sensing data and models as well as targeted orbital information acquired from Mars Global Surveyor and Mars Odyssey. This evaluation resulted in a number of predictions of the surface characteristics of the sites, which are tested in this abstract. Relating remote sensing signatures to surface characteristics at landing sites allows these sites to be used as ground truth for the orbital data, is essential for selecting and validating landing sites for future missions, and is required for correctly interpreting the surfaces and materials globally present on Mars.

Golombek, M.↗
NASA NTRS2002

MER landing site radar data

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Mars radar MOLA MGS laser altimeter scale roughnes↗