Open Access
Chemical heterogeneity on Mercury's surface revealed by the MESSENGER X-Ray Spectrometer
Shoshana Z. Weider,Larry R. Nittler,R. Starr,R. Starr,Timothy J. McCoy,Karen R. Stockstill-Cahill,Paul K. Byrne,Brett W. Denevi,James W. Head,Sean C. Solomon,Sean C. Solomon +10 more
TLDR
In this article, the analysis of 205 spatially resolved measurements of the surface composition of Mercury from MESSENGER's X-Ray Spectrometer is presented, and the surface footprints of these measurements are categorized according to geological terrain.Abstract:
[1] We present the analysis of 205 spatially resolved measurements of the surface composition of Mercury from MESSENGER’s X-Ray Spectrometer. The surface footprints of these measurements are categorized according to geological terrain. Northern smooth plains deposits and the plains interior to the Caloris basin differ compositionally from older terrain on Mercury. The older terrain generally has higher Mg/Si, S/Si, and Ca/Si ratios, and a lower Al/Si ratio than the smooth plains. Mercury’s surface mineralogy is likely dominated by high-Mg mafic minerals (e.g., enstatite), plagioclase feldspar, and lesser amounts of Ca, Mg, and/or Fe sulfides (e.g., oldhamite). The compositional difference between the volcanic smooth plains and the older terrain reflects different abundances of these minerals and points to the crystallization of the smooth plains from a more chemically evolved magma source. High-degree partial melts of enstatite chondrite material provide a generally good compositional and mineralogical match for much of the surface of Mercury. An exception is Fe, for which the low surface abundance on Mercury is still higher than that of melts from enstatite chondrites and may indicate an exogenous contribution from meteoroid impacts.read more
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Journal ArticleDOI
The distribution and origin of smooth plains on Mercury
Brett W. Denevi,Carolyn M. Ernst,Heather Meyer,Mark S. Robinson,Scott L. Murchie,Jennifer L. Whitten,James W. Head,Thomas R. Watters,Sean C. Solomon,Sean C. Solomon,Lillian R. Ostrach,Clark R. Chapman,Paul K. Byrne,Christian Klimczak,Patrick N. Peplowski +14 more
TL;DR: In this article, the MESSENGER images from the MRS spacecraft show that ~27% of Mercury's surface is covered by smooth plains, the majority of which are interpreted to be volcanic in origin, suggesting high temperatures and high degrees of partial melting in magma source regions persisted through most of the duration of smooth plains formation.
Journal ArticleDOI
Major-Element Abundances on the Surface of Mercury: Results from the MESSENGER Gamma-Ray Spectrometer
Larry G. Evans,Patrick N. Peplowski,Edgar A. Rhodes,David J. Lawrence,Timothy J. McCoy,Larry R. Nittler,Sean C. Solomon,Sean C. Solomon,Ann L. Sprague,Karen R. Stockstill-Cahill,R. D. Starr,Shoshana Z. Weider,William V. Boynton,D. K. Hamara,John O. Goldsten +14 more
TL;DR: In this paper, the gamma-ray and X-ray measurements obtained by the MESSENGER spacecraft have been analyzed to determine the abundances of the major elements Al, Ca, S, Fe, and Na on the surface of Mercury.
Journal ArticleDOI
Evidence for water ice near Mercury's north pole from MESSENGER Neutron Spectrometer measurements.
David J. Lawrence,W. C. Feldman,John O. Goldsten,Sylvestre Maurice,Patrick N. Peplowski,Brian J. Anderson,David Bazell,Ralph L. McNutt,Larry R. Nittler,Thomas H. Prettyman,D. J. Rodgers,Sean C. Solomon,Sean C. Solomon,Shoshana Z. Weider +13 more
TL;DR: MESSENGER neutron data reported by Lawrence et al. now confirm that the primary component of radar-reflective material at Mercury's north pole is water ice, and spacecraft data and a thermal model show that water ice and organic volatiles are present at Mercury’s north pole.
Journal ArticleDOI
Mercury’s global contraction much greater than earlier estimates
Paul K. Byrne,Paul K. Byrne,Christian Klimczak,A. M. Celâl Şengör,Sean C. Solomon,Sean C. Solomon,Thomas R. Watters,Steven A. Hauck +7 more
TL;DR: The authors mapped folds and faults across Mercury's surface using MESSENGER spacecraft images and revealed deformation consistent with a planet that has contracted radially as much as seven kilometres over its history.
Journal ArticleDOI
Evidence for geochemical terranes on Mercury: Global mapping of major elements with MESSENGER's X-Ray Spectrometer
Shoshana Z. Weider,Larry R. Nittler,R. D. Starr,E. J. Crapster-Pregont,E. J. Crapster-Pregont,Patrick N. Peplowski,Brett W. Denevi,James W. Head,Paul K. Byrne,Paul K. Byrne,Steven A. Hauck,Denton S. Ebel,Denton S. Ebel,Sean C. Solomon,Sean C. Solomon +14 more
TL;DR: In this article, the major-element composition of the surface of Mercury was mapped from orbital MESSENGER X-Ray Spectrometer measurements, and the results revealed highly variable compositions (e.g., Mg/Si and Al/Si range over 0.1 − 0.8 and 0.4, respectively).
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