D
D. K. Hamara
Researcher at University of Arizona
Publications - 59
Citations - 4426
D. K. Hamara is an academic researcher from University of Arizona. The author has contributed to research in topics: Mars Exploration Program & Martian. The author has an hindex of 25, co-authored 57 publications receiving 3904 citations.
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Journal ArticleDOI
Distribution of Hydrogen in the Near-Surface of Mars: Evidence for Subsurface Ice Deposits
William V. Boynton,W. C. Feldman,S. W. Squyres,Thomas H. Prettyman,J. Brückner,Larry G. Evans,R. C. Reedy,R. C. Reedy,R. D. Starr,James R. Arnold,D. M. Drake,P. Englert,Albert E. Metzger,I. G. Mitrofanov,Jacob I. Trombka,Claude d’Uston,Heinrich Wänke,Olivier Gasnault,D. K. Hamara,Daniel M. Janes,Robert L. Marcialis,Sylvestre Maurice,I. Mikheeva,G. J. Taylor,R. L. Tokar,C. Shinohara +25 more
TL;DR: The Gamma-Ray Spectrometer on the Mars Odyssey has identified two regions near the poles that are enriched in hydrogen, and it is suggested that the host of the hydrogen in the subsurface layer is ice, which constitutes 35 ± 15% of the layer by weight.
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The Major-Element Composition of Mercury’s Surface from MESSENGER X-ray Spectrometry
Larry R. Nittler,R. D. Starr,Shoshana Z. Weider,Timothy J. McCoy,William V. Boynton,Denton S. Ebel,Carolyn M. Ernst,Larry G. Evans,John O. Goldsten,D. K. Hamara,David J. Lawrence,Ralph L. McNutt,C. E. Schlemm,Sean C. Solomon,Ann L. Sprague +14 more
TL;DR: X-ray fluorescence spectra obtained by the MESSENGENGER spacecraft orbiting Mercury indicate that the planet's surface differs in composition from those of other terrestrial planets as discussed by the authors, and this observation, together with a low surface Fe abundance, supports the view that Mercury formed from highly reduced precursor materials, perhaps akin to enstatite chondrite meteorites or anhydrous cometary dust particles.
Journal ArticleDOI
Maps of subsurface hydrogen from the high energy neutron detector, Mars Odyssey.
I. G. Mitrofanov,D. Anfimov,Andrey V. Kozyrev,M. L. Litvak,A. B. Sanin,Vladislav Tretyakov,Anna I. Krylov,V. N. Shvetsov,William V. Boynton,C. Shinohara,D. K. Hamara,R. S. Saunders +11 more
TL;DR: In this article, the authors found deficits of high-energy neutrons in the southern highlands and northern lowlands of Mars, indicating that hydrogen is concentrated in the subsurface.
Journal ArticleDOI
Evidence for Calcium Carbonate at the Mars Phoenix Landing Site
William V. Boynton,D. W. Ming,Samuel P. Kounaves,S. M. M. Young,Raymond E. Arvidson,Michael H. Hecht,John H. Hoffman,Paul B. Niles,D. K. Hamara,Richard C. Quinn,Peter H. Smith,Brad Sutter,David C. Catling,David C. Catling,R. V. Morris +14 more
TL;DR: Results suggest that the soil at the Phoenix landing site must have suffered alteration through the action of liquid water in geologically the recent past, and an alkaline environment was revealed, in contrast to that found by the Mars Exploration Rovers, indicating that many different environments have existed on Mars.
Journal ArticleDOI
The Mars Odyssey Gamma-Ray Spectrometer Instrument Suite
William V. Boynton,W. C. Feldman,I. G. Mitrofanov,Larry G. Evans,Robert C. Reedy,Steven W. Squyres,R. D. Starr,Jacob I. Trombka,Claude d’Uston,James R. Arnold,P. A. J. Englert,Albert E. Metzger,Heinrich Wänke,J. Brückner,D. M. Drake,C. Shinohara,C. Fellows,D. K. Hamara,K. Harshman,K. Kerry,C. Turner,Martin Ward,H. Barthe,K. R. Fuller,S. A. Storms,G. W. Thornton,J. L. Longmire,M. L. Litvak,A. K. Ton'chev +28 more
TL;DR: The Mars Odyssey Gamma-Ray Spectrometer (MOGRS) is a suite of three different instruments, a gamma subsystem (GS), a neutron spectrometer, and a high-energy neutron detector, working together to collect data that will permit the mapping of elemental concentrations on the surface of Mars.