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Trent M. Hare

Publications and source records attributed to Trent M. Hare.

At least 37 records · Page 2Linked to original sources
USGS2014

The digital global geologic map of Mars: Chronostratigraphic ages, topographic and crater morphologic characteristics, and updated resurfacing history

A new global geologic map of Mars has been completed in a digital, geographic information system (GIS) format using geospatially controlled altimetry and image data sets. The map reconstructs the geologic history of Mars, which includes many new findings collated in the quarter century since the previous, Viking-based global maps were published, as well as other discoveries that were made during the course of the mapping using new data sets. The technical approach enabled consistent and regulated mapping that is appropriate not only for the map's 1:20,000,000 scale but also for its widespread use by diverse audiences. Each geologic unit outcrop includes basic attributes regarding identity, location, area, crater densities, and chronostratigraphic age. In turn, units are grouped by geographic and lithologic types, which provide synoptic global views of material ages and resurfacing character for the Noachian, Hesperian, and Amazonian periods. As a consequence of more precise and better quality topographic and morphologic data and more complete crater-density dating, our statistical comparisons identify significant refinements for how Martian geologic terrains are characterized. Unit groups show trends in mean elevation and slope that relate to geographic occurrence and geologic origin. In comparison with the previous global geologic map series based on Viking data, the new mapping consists of half the number of units due to simpler, more conservative and globally based approaches to discriminating units. In particular, Noachian highland surfaces overall have high percentages of their areas now dated as an epoch older than in the Viking mapping. Minimally eroded (i.e., pristine) impact craters ≥3 km in diameter occur in greater proportion on Hesperian surfaces. This observation contrasts with a deficit of similarly sized craters on heavily cratered and otherwise degraded Noachian terrain as well as on young Amazonian surfaces. We interpret these as reflecting the relatively stronger, lava-rich, yet less-impacted materials making up much of the younger units. Reconstructions of resurfacing of Mars by its eight geologic epochs using the Hartmann and Neukum chronology models indicate high rates of highland resurfacing during the Noachian (peaking at 0.3 km 2 /yr during the Middle Noachian), modest rates of volcanism and transition zone and lowland resurfacing during the Hesperian (∼0.1 km 2 /yr), and low rates of mainly volcanic and polar resurfacing (∼0.01 km 2 /yr) for most of the Amazonian. Apparent resurfacing increased in the Late Amazonian (∼0.03 km 2 /yr), perhaps due to better preservation of this latest record.

Planetary and Space Science↗
USGS2014

Summary and abstracts of the Planetary Data Workshop, June 2012

The recent boom in the volume of digital data returned by international planetary science missions continues to both delight and confound users of those data. In just the past decade, the Planetary Data System (PDS), NASA’s official archive of scientific results from U.S. planetary missions, has seen a nearly 50-fold increase in the amount of data and now serves nearly half a petabyte. In only a handful of years, this volume is expected to approach 1 petabyte (1,000 terabytes or 1 quadrillion bytes). Although data providers, archivists, users, and developers have done a creditable job of providing search functions, download capabilities, and analysis and visualization tools, the new wealth of data necessitates more frequent and extensive discussion among users and developers about their current capabilities and their needs for improved and new tools. A workshop to address these and other topics, “Planetary Data: A Workshop for Users and Planetary Software Developers,” was held June 25–29, 2012, at Northern Arizona University (NAU) in Flagstaff, Arizona. A goal of the workshop was to present a summary of currently available tools, along with hands-on training and how-to guides, for acquiring, processing and working with a variety of digital planetary data. The meeting emphasized presentations by data users and mission providers during days 1 and 2, and developers had the floor on days 4 and 5 using an “unconference” format for day 5. Day 3 featured keynote talks by Laurence Soderblom (U.S. Geological Survey, USGS) and Dan Crichton (Jet Propulsion Laboratory, JPL) followed by a panel discussion, and then research and technical discussions about tools and capabilities under recent or current development. Software and tool demonstrations were held in break-out sessions in parallel with the oral session. Nearly 150 data users and developers from across the globe attended, and 22 National Aeronautics and space Administration (NASA) and non-NASA data providers and missions were represented. Presentations (some in video format) and tutorials are posted on the meeting site ( http://astrogeology.usgs.gov/groups/Planetary-Data-Workshop ).

Open-File Report↗
USGS2014

Geologic map of Mars

This global geologic map of Mars, which records the distribution of geologic units and landforms on the planet's surface through time, is based on unprecedented variety, quality, and quantity of remotely sensed data acquired since the Viking Orbiters. These data have provided morphologic, topographic, spectral, thermophysical, radar sounding, and other observations for integration, analysis, and interpretation in support of geologic mapping. In particular, the precise topographic mapping now available has enabled consistent morphologic portrayal of the surface for global mapping (whereas previously used visual-range image bases were less effective, because they combined morphologic and albedo information and, locally, atmospheric haze). Also, thermal infrared image bases used for this map tended to be less affected by atmospheric haze and thus are reliable for analysis of surface morphology and texture at even higher resolution than the topographic products.

Scientific Investigations Map↗
USGS2012

Progress on archiving, delivering, and working with planetary data

Planetary Data: A Workshop for Users and Software Developers 2012; Flagstaff, Ariz., 25–29 June 2012 The recent boom in the volume of data returned by planetary science missions continues to delight and confound users. Recently the NASA Planetary Data System (PDS) has seen an approximately 50‐fold increase in the amount of archived data and now serves nearly half a petabyte. Within 5 years, this volume likely will approach 1 petabyte. While archivists, users, and developers have done a creditable job of providing search and download functions and analysis and visualization tools, the wealth of data necessitates more discussion between users and developers about current limitations and desired improvements.

Eos, Transactions, American Geophysical Union↗
USGS2009

Strategic analysis for the MER Cape Verde approach

The Mars Exploration Rover Opportunity has recently completed a two year campaign studying Victoria Crater. The campaign culminated in a close approach of Cape Verde in order to acquire high resolution imagery of the exposed stratigraphy in the cliff face. The close approach to Cape Verde provided significant challenges for every subsystem of the rover as the rover needed to traverse difficult, uncharacterised terrain and approach a cliff face with the potential of blocking out solar energy and communications with Earth. In this paper we describe the strategic analyses performed by the science and engineering teams so that we could successfully achieve the science objectives while keeping the rover safe. ??2009 IEEE.

Conference Paper↗
USGS2008

Ultrahigh resolution topographic mapping of Mars with MRO HiRISE stereo images: Meter-scale slopes of candidate Phoenix landing sites

The objectives of this paper are twofold: first, to report our estimates of the meter‐to‐decameter‐scale topography and slopes of candidate landing sites for the Phoenix mission, based on analysis of Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) images with a typical pixel scale of 3 m and Mars Reconnaissance Orbiter (MRO) High Resolution Imaging Science Experiment (HiRISE) images at 0.3 m pixel −1 and, second, to document in detail the geometric calibration, software, and procedures on which the photogrammetric analysis of HiRISE data is based. A combination of optical design modeling, laboratory observations, star images, and Mars images form the basis for software in the U.S. Geological Survey Integrated Software for Imagers and Spectrometers (ISIS) 3 system that corrects the images for a variety of distortions with single‐pixel or subpixel accuracy. Corrected images are analyzed in the commercial photogrammetric software SOCET SET (® BAE Systems), yielding digital topographic models (DTMs) with a grid spacing of 1 m (3–4 pixels) that require minimal interactive editing. Photoclinometry yields DTMs with single‐pixel grid spacing. Slopes from MOC and HiRISE are comparable throughout the latitude zone of interest and compare favorably with those where past missions have landed successfully; only the Mars Exploration Rover (MER) B site in Meridiani Planum is smoother. MOC results at multiple locations have root‐mean‐square (RMS) bidirectional slopes of 0.8–4.5° at baselines of 3–10 m. HiRISE stereopairs (one per final candidate site and one in the former site) yield 1.8–2.8° slopes at 1‐m baseline. Slopes at 1 m from photoclinometry are also in the range 2–3° after correction for image blur. Slopes exceeding the 16° Phoenix safety limit are extremely rare.

Journal of Geophysical Research E: Planets↗
USGS2008

Surface processes recorded by rocks and soils on Meridiani Planum, Mars: Microscopic Imager observations during Opportunity's first three extended missions

The Microscopic Imager (MI) on the Mars Exploration Rover Opportunity has returned images of Mars with higher resolution than any previous camera system, allowing detailed petrographic and sedimentological studies of the rocks and soils at the Meridiani Planum landing site. Designed to simulate a geologist's hand lens, the MI is mounted on Opportunity's instrument arm and can resolve objects 0.1 mm across or larger. This paper provides an overview of MI operations, data calibration, and analysis of MI data returned during the first 900 sols (Mars days) of the Opportunity landed mission. Analyses of Opportunity MI data have helped to resolve major questions about the origin of observed textures and features. These studies support eolian sediment transport, rather than impact surge processes, as the dominant depositional mechanism for Burns formation strata. MI stereo observations of a rock outcrop near the rim of Erebus Crater support the previous interpretation of similar sedimentary structures in Eagle Crater as being formed by surficial flow of liquid water. Well‐sorted spherules dominate ripple surfaces on the Meridiani plains, and the size of spherules between ripples decreases by about 1 mm from north to south along Opportunity's traverse between Endurance and Erebus craters.

Journal of Geophysical Research E: Planets↗
USGS2007

Mars global digital dune database and initial science results

A new Mars Global Digital Dune Database (MGD 3 ) constructed using Thermal Emission Imaging System (THEMIS) infrared (IR) images provides a comprehensive and quantitative view of the geographic distribution of moderate‐ to large‐size dune fields (area >1 km 2 ) that will help researchers to understand global climatic and sedimentary processes that have shaped the surface of Mars. MGD 3 extends from 65°N to 65°S latitude and includes ∼550 dune fields, covering ∼70,000 km 2 , with an estimated total volume of ∼3,600 km 3 . This area, when combined with polar dune estimates, suggests moderate‐ to large‐size dune field coverage on Mars may total ∼800,000 km 2 , ∼6 times less than the total areal estimate of ∼5,000,000 km 2 for terrestrial dunes. Where availability and quality of THEMIS visible (VIS) or Mars Orbiter Camera narrow‐angle (MOC NA) images allow, we classify dunes and include dune slipface measurements, which are derived from gross dune morphology and represent the prevailing wind direction at the last time of significant dune modification. For dunes located within craters, the azimuth from crater centroid to dune field centroid (referred to as dune centroid azimuth) is calculated and can provide an accurate method for tracking dune migration within smooth‐floored craters. These indicators of wind direction are compared to output from a general circulation model (GCM). Dune centroid azimuth values generally correlate to regional wind patterns. Slipface orientations are less well correlated, suggesting that local topographic effects may play a larger role in dune orientation than regional winds.

Journal of Geophysical Research E: Planets↗
USGS2007

Topography and geomorphology of the Huygens landing site on Titan

The Descent Imager/Spectral Radiometer (DISR) aboard the Huygens Probe took several hundred visible-light images with its three cameras on approach to the surface of Titan. Several sets of stereo image pairs were collected during the descent. The digital terrain models constructed from those images show rugged topography, in places approaching the angle of repose, adjacent to flatter darker plains. Brighter regions north of the landing site display two styles of drainage patterns: (1) bright highlands with rough topography and deeply incised branching dendritic drainage networks (up to fourth order) with dark-floored valleys that are suggestive of erosion by methane rainfall and (2) short, stubby low-order drainages that follow linear fault patterns forming canyon-like features suggestive of methane spring-sapping. The topographic data show that the bright highland terrains are extremely rugged; slopes of order of 30° appear common. These systems drain into adjacent relatively flat, dark lowland terrains. A stereo model for part of the dark plains region to the east of the landing site suggests surface scour across this plain flowing from west to east leaving ∼100-m-high bright ridges. Tectonic patterns are evident in (1) controlling the rectilinear, low-order, stubby drainages and (2) the “coastline” at the highland–lowland boundary with numerous straight and angular margins. In addition to flow from the highlands drainages, the lowland area shows evidence for more prolific flow parallel to the highland–lowland boundary leaving bright outliers resembling terrestrial sandbars. This implies major west to east floods across the plains where the probe landed with flow parallel to the highland–lowland boundary; the primary source of these flows is evidently not the dendritic channels in the bright highlands to the north.

Planetary and Space Science↗
USGS2007

Report on the final completion of the Unified Lunar Control Network 2005 and Lunar Topographic Model

In order to highlight this project to the extraterrestrial mapping community, we repeat here our earlier abstract [1], with a corrected Figure 2. A report describing the Unified Lunar Control Network 2005 and the files associated with that network is now available as an on-line USGS Open-File Report [2] at the location http://pubs.usgs.gov/of/2006/1367/. A “Readme” file describes the available files, including the report text, the original photogrammetric solution input and output files, derived files such as information on all the control point positions, the expected vertical precision (EVP) of the points and the solution residuals, and a directory containing global DEMs derived from the point positions. While a paper providing further details about the solution is in preparation, we provide some useful additional information about the solution and possible uses for it here.

Conference Paper↗
USGS2007

Urgent processing and control of lunar data

There is an urgent, time-critical need to begin tying together (geodetically controlling) all past and current lunar data, and to establish the cartographic foundation needed to make maximum use of future planned lunar data. Proper control of lunar datails required to properly support both lunar science and exploration, and at present we know of no plans within NASA to fund such work adequately. The utility of past and future lunar data will be severely hampered if they cannot be correlated/compared with each other or if the uncertainties in the positional accuracies are not well characterized. Since “required capabilities” and “technology developments” are on the primary list of issues for this workshop [1], it is clear that this issue is not only appropriate but critical to discuss and that strong recommendations must be made to address this problem. This white paper summarizes more detailed discussions that we have presented earlier [2].

Conference Paper↗
USGS2006

Overview of the Microscopic Imager Investigation during Spirit's first 450 sols in Gusev crater

The Microscopic Imager (MI) on the Mars Exploration Rover Spirit has returned images of Mars with higher resolution than any previous camera system, allowing detailed petrographic and sedimentological studies of the rocks and soils at the Gusev landing site. Designed to simulate a geologist's hand lens, the MI is mounted on Spirit's instrument arm and can resolve objects 0.1 mm in size or larger. This paper provides an overview of MI operations, data calibration, processing, and analysis of MI data returned during the first 450 sols (Mars days) of the Spirit landed mission. The primary goal of this paper is to facilitate further analyses of MI data by summarizing the methods used to acquire and process the data, the radiometric and geometric accuracy of MI data products, and the availability of archival products. In addition, scientific results of the MI investigation are summarized. MI observations show that poorly sorted soils are common in Gusev crater, although aeolian bedforms have well‐sorted coarse sand grains on their surfaces. Abraded surfaces of plains rocks show igneous textures, light‐toned veins or fracture‐filling minerals, and discrete coatings. The rocks in the Columbia Hills have a wide variety of granular textures, consistent with volcaniclastic or impact origins. Case hardening and submillimeter veins observed in the rocks as well as soil crusts and cemented clods imply episodic subsurface aqueous fluid movement, which has altered multiple geologic units in the Columbia Hills. The MI also monitored Spirit's solar panels and the magnets on the rover's deck.

Journal of Geophysical Research E: Planets↗
USGS2006

Topomapping of Mars with HRSC Images, ISIS, and a commercial stereo workstation

We demonstrate that the freely available USGS planetary cartography software package ISIS and the commercial photogrammetric software SOCET SET jointly provide a complete environment for the processing of Mars Express High Resolution Stereo Camera (HRSC) images. Capabilities include bundle adjustment, automated production and interactive editing of stereo digital terrain models (DTMs), orthomosaic production, photometric modeling and normalization, and DTM refinement by photoclinometry/shapefrom-shading. The generation of DTMs and other products for two test areas on Mars is described; a companion paper by Heipke et al. (2006) compares DTMs produced from these test datasets by multiple investigators using alternate approaches. SOCET SET capabilities relevant to multi-line scanners (including HRSC) are evolving, and improved performance in several areas can be expected in the near future. ISIS by itself provides useful capabilities for orthomosaic production with pre-existing DTMs, photometry, and photoclinometry, and the value of these free tools will be increased once an HRSC bundle-adjustment capability is implemented.

Conference Paper↗
USGS2005

Utility of Viking Orbiter images and products for Mars mapping

This paper reports on mapping procedures developed by the U.S. Geological Survey that use Viking Orbiter imagery and Mars Orbiter Laser Altimeter (MOLA) derived radii to produce topographic data. The use of Mosaiced Digital Image Models (MDIMs), created from Viking Orbiter images, and MOLA data to provide horizontal and vertical control is reviewed. We describe procedures to adapt a commercial digital photogrammetric workstation to work with planetary data.

Photogrammetric Engineering and Remote Sensing↗
USGS2005

Geologic map of the northern plains of Mars

The northern plains of Mars cover nearly a third of the planet and constitute the planet's broadest region of lowlands. Apparently formed early in Mars' history, the northern lowlands served as a repository both for sediments shed from the adjacent ancient highlands and for volcanic flows and deposits from sources within and near the lowlands. Geomorphic evidence for extensive tectonic deformation and reworking of surface materials through release of volatiles occurs throughout the northern plains. In the polar region, Planum Boreum contains evidence for the accumulation of ice and dust, and surrounding dune fields suggest widespread aeolian transport and erosion. The most recent regional- and global-scale maps describing the geology of the northern plains are largely based on Viking Orbiter image data (Dial, 1984; Witbeck and Underwood, 1984; Scott and Tanaka, 1986; Greeley and Guest, 1987; Tanaka and Scott, 1987; Tanaka and others, 1992a; Rotto and Tanaka, 1995; Crumpler and others, 2001; McGill, 2002). These maps reveal highland, plains, volcanic, and polar units based on morphologic character, albedo, and relative ages using local stratigraphic relations and crater counts. This geologic map of the northern plains is the first published map that covers a significant part of Mars using topography and image data from both the Mars Global Surveyor and Mars Odyssey missions. The new data provide a fresh perspective on the geology of the region that reveals many previously unrecognizable units, features, and temporal relations. In addition, we adapted and instituted terrestrial mapping methods and stratigraphic conventions that we think result in a clearer and more objective map. We focus on mapping with the intent of reconstructing the history of geologic activity within the northern plains, including deposition, volcanism, erosion, tectonism, impact cratering, and other processes with the aid of comprehensive crater-density determinations. Mapped areas include all plains regions within the northern hemisphere of Mars, as well as an approximately 300-km-wide strip of cratered highland and volcanic regions, which border the plains. Note that not all of the contiguous northern plains are mapped, because some minor parts of Elysium and Amazonis Planitiae lie south of the equator.

Scientific Investigations Map↗
USGS2003

High-resolution topomapping of candidate MER landing sites with Mars Orbiter Camera narrow-angle images

We analyzed narrow‐angle Mars Orbiter Camera (MOC‐NA) images to produce high‐resolution digital elevation models (DEMs) in order to provide topographic and slope information needed to assess the safety of candidate landing sites for the Mars Exploration Rovers (MER) and to assess the accuracy of our results by a variety of tests. The mapping techniques developed also support geoscientific studies and can be used with all present and planned Mars‐orbiting scanner cameras. Photogrammetric analysis of MOC stereopairs yields DEMs with 3‐pixel (typically 10 m) horizontal resolution, vertical precision consistent with ∼0.22 pixel matching errors (typically a few meters), and slope errors of 1–3°. These DEMs are controlled to the Mars Orbiter Laser Altimeter (MOLA) global data set and consistent with it at the limits of resolution. Photoclinometry yields DEMs with single‐pixel (typically ∼3 m) horizontal resolution and submeter vertical precision. Where the surface albedo is uniform, the dominant error is 10–20% relative uncertainty in the amplitude of topography and slopes after “calibrating” photoclinometry against a stereo DEM to account for the influence of atmospheric haze. We mapped portions of seven candidate MER sites and the Mars Pathfinder site. Safety of the final four sites (Elysium, Gusev, Isidis, and Meridiani) was assessed by mission engineers by simulating landings on our DEMs of “hazard units” mapped in the sites, with results weighted by the probability of landing on those units; summary slope statistics show that most hazard units are smooth, with only small areas of etched terrain in Gusev crater posing a slope hazard.

Journal of Geophysical Research E: Planets↗
USGS2003

Geology of the MER 2003 "Elysium" candidate landing site in southeastern Utopia Planitia, Mars

The NASA Mars Exploration Rover (MER) Project has been considering a landing-site ellipse designated EP78B2 in southeastern Utopia Planitia, southwest of Elysium Mons. The site appears to be relatively safe for a MER landing site because of its predicted low wind velocities in mesoscale atmospheric circulation models and its low surface roughness at various scales as indicated by topographic and imaging data sets. Previously, the site's surface rocks have been interpreted to be marine sediments or lava flows. In addition, we suggest that Late Noachian to Early Hesperian collapse and mass wasting of Noachian highland rocks contributed to the deposition of detritus in the area of the ellipse. Furthermore, we document partial Late Hesperian to Early Amazonian resurfacing of the ellipse by flows and vents that may be of mud or silicate volcanic origin. A rover investigation of the Utopia landing site using the MER Athena instrument package might address some fundamental aspects of Martian geologic evolution, such as climate change, hydrologic evolution, and magmatic and tectonic history.

Journal of Geophysical Research E: Planets↗