Loading…

Variations in the abundances of potassium and thorium on the surface of Mercury: Results from the MESSENGER Gamma-Ray Spectrometer

A technique for converting gamma‐ray count rates measured by the Gamma‐Ray Spectrometer on the MESSENGER spacecraft to spatially resolved maps of the gamma‐ray emission from the surface of Mercury is utilized to map the surface distributions of the elements Si, O, and K over the planet's northe...

Full description

Saved in:
Bibliographic Details
Published in:Journal of Geophysical Research: Planets 2012-12, Vol.117 (E12), p.n/a
Main Authors: Peplowski, Patrick N., Lawrence, David J., Rhodes, Edgar A., Sprague, Ann L., McCoy, Timothy J., Denevi, Brett W., Evans, Larry G., Head, James W., Nittler, Larry R., Solomon, Sean C., Stockstill-Cahill, Karen R., Weider, Shoshana Z.
Format: Article
Language:English
Subjects:
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A technique for converting gamma‐ray count rates measured by the Gamma‐Ray Spectrometer on the MESSENGER spacecraft to spatially resolved maps of the gamma‐ray emission from the surface of Mercury is utilized to map the surface distributions of the elements Si, O, and K over the planet's northern hemisphere. Conversion of the K gamma‐ray count rates to elemental abundances on the surface reveals variations from 300 to 2400 ppm. A comparison of these abundances with models for the maximum surface temperature suggests the possibility that a temperature‐related process is controlling the K abundances on the surface as well as providing K to the exosphere. The abundances of K and Th have been determined for several geologically distinct regions, including Mercury's northern smooth plains and the plains interior to the Caloris basin. The lack of a significant variation in the measured Th abundances suggests that there may be considerable variability in the K/Th abundance ratio over the mapped regions. Key Points First spatially resolved measurements of Si, O, K, and Th on Mercury K abundances vary significantly across the surface Potassium abundances may be driven by the thermal conditions on the surface
ISSN:0148-0227
2169-9097
2156-2202
2169-9100
DOI:10.1029/2012JE004141