Harry McSween

Harry McSween
University of Tennessee | UTK · Earth and Planetary Sciences

Doctor of Philosophy

About

935
Publications
59,064
Reads
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33,463
Citations
Citations since 2016
95 Research Items
10879 Citations
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201620172018201920202021202205001,0001,500
201620172018201920202021202205001,0001,500
201620172018201920202021202205001,0001,500
Introduction
Planetary science and exploration, meteoritics and cosmochemistry

Publications

Publications (935)
Article
Full-text available
Primitive achondrites of the acapulcoite–lodranite clan (ALC) are residues of partial melting that displays a continuum of thermal metamorphism and partial melting most likely set by burial depth within an internally heated, primordial acapulcoite–lodranite parent body (ALPB). New major and trace element data from eight ALC meteorites and the appli...
Article
Due to its size and observable record of ancient rock, Mars is key to understanding crustal formation on planetary bodies, including Venus and Earth, which may have derived their first stable crust from mantle-overturn melting. Recent evidence that ancient martian crust contains an evolved component supports inferences of a pervasive, buried feldsp...
Chapter
The NASA Dawn mission, launched in 2007, aimed to visit two of the most massive protoplanets of the main asteroid belt: Vesta and Ceres. The aim was to further our understanding of the earliest days of the Solar System, and compare the two bodies to better understand their formation and evolution. This book summarises state-of-the-art results from...
Article
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Dawn revealed that Ceres is a compelling target whose exploration pertains to many science themes. Ceres is a large ice- and organic-rich body, potentially representative of the population of objects that brought water and organics to the inner solar system, as well as a brine-rich body whose study can contribute to ocean world science. The Dawn ob...
Article
On Mars, impact craters that are proximal can exhibit vastly different thermal inertia values on their rims, even where the target lithology appears to be the same. Degradation of crater rims produces fine-grained regolith over time through comminution, and we investigated whether this process affects crater rim thermal inertia in regions with low...
Article
Full-text available
Plain Language Summary The outermost meter of dwarf planet Ceres contains water ice that is gradually sublimating in response to heating of the surface by sunlight. Since Ceres' axis of rotation is nearly perpendicular to the Sun's rays, ice has receded to greater depths at the equator than the poles. The distribution of subsurface ice within this...
Conference Paper
Full-text available
Introduction: New major and trace element data illuminate the magmatic and thermal evolution of the acapul-coite-lodranite parent body (ALPB). We observe major and trace element disequilibrium in the acapulcoite and transitional groups that provide evidence for melt infiltration and melt-rock reaction processes. In lodranites, which represent sourc...
Article
Ceres, a nearly 1000-km diameter body located in the Solar System’s main asteroid belt, has been classified under many categories: planet, comet, asteroid, minor planet and, presently, dwarf planet. No matter what the designation, Ceres has experienced major planetary processes. Its evolution has been controlled by water, making it a most unusual,...
Conference Paper
Full-text available
Studying primary crust formation for some planetary bodies, such as Venus and Earth, is challenging because no direct observations of their first stable crusts have been made, and indeed may never be made. Modeling work indicates that rocky bodies the size of Mars and larger will have derived their primary crusts from “overturn melting” [1], charac...
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Ordinary chondrites (OCs) are variably thermally metamorphosed meteorites thought to originate from at least three different parent bodies (H, L, and LL) in the Main Belt of asteroids. The thermal evolutions of OC parent bodies are frequently explained by the onion shell model; however, a competing hypothesis is the fragmentation-reassembly model....
Conference Paper
Full-text available
Ordinary chondrites (OCs) are variably thermally metamorphosed meteorites thought to originate from three different asteroid parent bodies (H, L, and LL). Their thermal evolutions are frequently explained by the onion shell model; however, a competing hypothesis is the fragmentation-reassembly model. The onion shell model proposes an internally hea...
Conference Paper
Full-text available
Introduction: Primitive achondrites include several groups of stony meteorites that are residues of low-degrees of partial melting, hence they have experienced higher temperatures (temps) than chondritic meteorites. Cosmochemical, oxygen isotope, and cosmic ray exposure age data for several primitive achondrite groups (and associated silicate-beari...
Article
Quantifying the amounts of various igneous lithologies in Vesta’s crust allows the estimation of petrologic ratios that describe the asteroid’s global differentiation and subsequent magmatic history. The eucrite:diogenite (Euc:Diog) ratio measures the relative proportions of mafic and ultramafic components. The intrusive:extrusive (I:E) ratio asses...
Conference Paper
Full-text available
Ordinary chondrites (OCs) are thought to originate from three different parent bodies (H, L, LL). Their thermal evolutions are typically explained via two competing models; the classic onion shell model or the fragmentation-reassembly model. The onion shell model predicts that OC petrologic types (i.e., 3 to 6) develop with increasing temperature a...
Book
Cambridge Core - History of Astronomy and Cosmology - Planetary Geoscience - by Harry Y. McSween, Jr
Article
Full-text available
Return of samples from the surface of Mars has been a goal of the international Mars science community for many years. Strategies for the collection of such samples have ranged from “grab and go” acquisition from the surface, to dust collection in the atmosphere, to scientific selection by geologically capable rovers. As comprehension of the comple...
Article
Full-text available
Return of samples from the surface of Mars has been a goal of the international Mars science community for many years. Affirmation by NASA and ESA of the importance of Mars exploration led the agencies to establish the international MSR Objectives and Samples Team (iMOST). The purpose of the team is to re‐evaluate and update the sample‐related scie...
Article
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This report requested by the International Mars Exploration Working Group (IMEWG). Return of samples from the surface of Mars has been a goal of the international Mars science community for many years. Affirmation by NASA and ESA of the importance of Mars exploration led the agencies to establish the international MSR Objectives and Samples Team (i...
Article
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Larkman Nunatak (LAR) 12095 and LAR 12240 are recent olivine‐phyric shergottite finds. We report the results of petrographic and chemical analyses of these two samples to understand their petrogenesis on Mars. Based on our analyses, we suggest that these samples are likely paired and are most similar to other depleted olivine‐phyric shergottites, p...
Chapter
Proposed biosignatures in the ancient Allan Hills 84001 martian meteorite are most plausibly explained as abiotic features. The purported evidence of biological activity on Mars included biogenic minerals (magnetite and sulphide formed by magnetotactic and sulphate-respiring microorganisms), organic matter resulting from the decay of such organisms...
Conference Paper
Full-text available
Introduction: Thermal evolution models of asteroids are ground-truthed by estimates of temperatures (hereafter temps) and cooling rates from meteorite cosmochemical data [e.g., 1]. However, traditional geothermometers used to constrain the thermal evolution of meteorite parent bodies typically record blocking temps during cooling rather than peak o...
Article
Full-text available
Except for asteroid sample return missions, measurements of the spectral properties of both meteorites and asteroids offer the best possibility of linking meteorite groups with their parent asteroid(s). Visible plus near‐infrared spectra reveal distinguishing absorption features controlled mainly by the Fe²⁺ contents and modal abundances of olivine...
Book
Full-text available
Executive Summary: Return of samples from the surface of Mars has been a goal of the international Mars science community for many years. Affirmation by NASA and ESA of the importance of Mars exploration led the agencies to establish the international MSR Objectives and Samples Team (iMOST). The purpose of the team is to re-evaluate and update the...
Article
Inspired by the recent results of the Dawn mission, thermodynamic models of rock alteration and brine evaporation have been used to help understand the conditions under which water–rock interaction took place within the dwarf planet Ceres. This analysis constrains Ceres's early history and offers a framework within which future observations may be...
Conference Paper
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The analysis in Earth laboratories of samples that could be returned from Mars is of extremely high interest to the international Mars exploration community. IMEWG (the International Mars Exploration Working Group) has been evaluating options, by means of a working group referred to as iMOST, to refine the scientific objectives of MSR. The Mars 202...
Article
Impact craters across Mars, that are otherwise similar, commonly exhibit vastly different thermal inertia values on their rims. We focused on the Tisia Valles region because the terrain is mostly flat, and craters of various ages are present within the same target geologic unit. We present an investigation of two hypotheses for why these thermal in...
Article
Combined analyses of the surface elemental composition and mineralogy of Vesta and Ceres provide insights into their interior evolution, crustal formation, and regolith processes. Compositional data acquired by Dawn's Visible to Infrared Mapping Spectrometer (VIR) and Gamma Ray and Neutron Detector (GRaND) are sensitive to different depths and spat...
Article
The recent discovery of some ancient evolved rocks in Gale crater by the Curiosity rover has prompted the hypothesis that continental crust formed in early Martian history. Here we present petrological modeling that attempts to explain this lithological diversity by magma fractionation. Using the thermodynamical software MELTS, we model fractional...
Article
The Roebling Medal recognizes outstanding research in mineral sciences, and this year's medalist—Edward Stolper—conducts experiments that are arguably the most original and innovative of this generation. His interpretations and insights often upend current thinking and, in the process, turn misconceptions and nonsense into solid gold. Ed's early re...
Article
We investigated several olivine-bearing, medium-grained, ophitic to subophitic eucritic clasts from three different Antarctic howardites. Based on grain size (0.5–2 mm), these clasts could represent intrusive igneous units. Based on mineral composition (pyroxene and plagioclase), they are similar to basaltic eucrites. Elemental concentrations of th...
Article
The use of Residual Gas Analyzers (RGAs) during irradiation experiments can provide valuable information when incorporated into experimental end-stations. The instruments can track the volatilization products of beam-sensitive materials, which may ultimately aid researchers in selecting appropriate flux values for conducting experiments. Furthermor...
Conference Paper
Full-text available
Introduction: Models of the thermal evolution of meteorite parent asteroids are predicated on geothermometric estimates of temperatures and cooling rates achieved on those bodies [e.g., 1]. However, geothermometers used to constrain the thermal evolution of asteroids typically record blocking temperatures during cooling rather than peak or magmatic...
Article
Full-text available
We describe petrographic, electron microprobe, and laser ablation ICP-MS analyses of Mg-rich harzburgite clasts in the Dominion Range 2010 howardites, and conclude that they are xenolithic samples of the vestan mantle. Key chemical and petrologic characteristics of these rocks provide tests for differentiation models. Our results indicate the mantl...
Article
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The mineralogy and geochemistry of Ceres, as constrained by Dawn's instruments, are broadly consistent with a carbonaceous chondrite (CM/CI) bulk composition. Differences explainable by Ceres’s more advanced alteration include the formation of Mg-rich serpentine and ammoniated clay; a greater proportion of carbonate and lesser organic matter; amoun...
Article
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The Dominion Range 2010 howardite pairing group contains an evolved lithic clast of dacite composition. The dacite contains an assemblage of plagioclase, quartz, and augite, with minor pigeonite, troilite, ilmenite, FeNi metal, K-feldspar, and phosphates. Primary augite occurs as >1 mm oikocrysts enclosing plagioclase. Quartz is abundant, comprisin...
Article
The Visible and Infrared Spectrometer (VIR) instrument on the Dawn mission observed Ceres’s surface at different spatial resolutions, revealing a nearly uniform global distribution of surface mineralogy. Clearly, Ceres experienced extensive water‐related processes and chemical differentiation. The surface is mainly composed of a dark component (car...
Article
Organic compounds detected on Ceres Water and organic molecules were delivered to the early Earth by the impacts of comets and asteroids. De Sanctis et al. examined infrared spectra taken by the Dawn spacecraft as it orbited Ceres, the largest object in the asteroid belt (see the Perspective by Küppers). In some small patches on the surface, they d...
Chapter
Processes governing the evolution of planetesimals are critical to understanding how rocky planets are formed, how water is delivered to them, the origin of planetary atmospheres, how cores and magnetic dynamos develop, and ultimately, which planets have the potential to be habitable. Theoretical advances and new data from asteroid and meteorite ob...
Article
We use data collected by the Dawn Gamma-Ray and Neutron Detector (GRaND) at Vesta to map compositions corresponding to nearly pure igneous lithologies in the howardite, eucrite, diogenite (HED) meteorite clan (samples likely from Vesta). At the ∼300-km spatial scale of GRaND measurements, basaltic eucrite occurs on only 3% of the surface, whereas c...
Conference Paper
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Dawn at Ceres: What We Have Learned
Conference Paper
Full-text available