Space weathering on airless planetary bodies: Clues from the lunar mineral hapkeite
- 26 April 2004
- journal article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences of the United States of America
- Vol. 101 (18), 6847-6851
- https://doi.org/10.1073/pnas.0401565101
Abstract
Physical and chemical reactions occurring as a result of the high-velocity impacts of meteorites and micrometeorites and of cosmic rays and solar-wind particles are major causes of space weathering on airless planetary bodies, such as the Moon, Mercury, and asteroids. These weathering processes are responsible for the formation of their regolith and soil. We report here the natural occurrence of the mineral hapkeite, a Fe2Si phase, and other associated Fe-Si phases (iron-silicides) in a regolith breccia clast of a lunar highland meteorite. These Fe-Si phases are considered to be a direct product of impact-induced, vapor-phase deposition in the lunar soil, all part of space weathering. We have used an in situ synchrotron energy-dispersive, single-crystal x-ray diffraction technique to confirm the crystal structure of hapkeite as similar to the structure of synthetic Fe2Si. This mineral, hapkeite, is named after Bruce Hapke of the University of Pittsburgh, who predicted the presence and importance of vapor-deposited coatings on lunar soil grains some 30 years ago. We propose that this mineral and other Fe-Si phases are probably more common in the lunar regolith than previously thought and are directly related to the formation of vapor-deposited, nanophase elemental iron in the lunar soils.Keywords
This publication has 24 references indexed in Scilit:
- Lunar Mare Soils: Space weathering and the major effects of surface‐correlated nanophase FeJournal of Geophysical Research, 2001
- Space weathering from Mercury to the asteroid beltJournal of Geophysical Research, 2001
- The effects of space weathering on Apollo 17 mare soils: Petrographie and chemical characterizationMeteoritics & Planetary Science, 2001
- X-Ray Digital Imaging Petrography of Lunar Mare Soils: Modal Analyses of Minerals and GlassesIcarus, 1996
- Vapor Deposits in the Lunar RegolithScience, 1994
- Vapor Deposits in the Lunar RegolithScience, 1994
- Discovery of Vapor Deposits in the Lunar RegolithScience, 1993
- Lightning Strike Fusion: Extreme Reduction and Metal-Silicate Liquid ImmiscibilityScience, 1986
- Kristallstruktur von Fe2Si(h)Journal of the Less Common Metals, 1974
- Ultrathin Amorphous Coatings on Lunar Dust GrainsScience, 1972