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Solar flare and galactic cosmic ray tracks in lunar samples and meteorites - What they tell us about the ancient sunEvidence regarding the past activity of the sun in the form of nuclear particle tracks in lunar samples and meteorites produced by heavy ions in galactic cosmic rays and solar flares is reviewed. Observations of track-rich grains found in deep lunar cores and meteorite interiors are discussed which demonstrate the presence of solar flare activity for at least the past 4 billion years, and the similarity of track density profiles from various lunar and meteoritic samples with those in a glass filter from Surveyor 3 exposed at the lunar surface for almost three years is presented as evidence of the relative constancy of the solar flare energy spectrum over the same period. Indications of a heavy ion enrichment in solar flares are considered which are confirmed by recent satellite measurements, although difficult to quantify in lunar soil grains. Finally, it is argued that, despite previous claims, there exists as yet no conclusive evidence for either a higher solar activity during the early history of the moon or a change in galactic cosmic ray intensity, average composition or spectrum over the last 50 million years.
Document ID
19810064421
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Crozaz, G.
(Washington University St. Louis, MO, United States)
Date Acquired
August 11, 2013
Publication Date
January 1, 1980
Subject Category
Lunar And Planetary Exploration
Meeting Information
Meeting: Conference on The ancient sun: Fossil record in the earth, moon and meteorites
Location: Boulder, CO
Start Date: October 16, 1979
End Date: October 19, 1979
Accession Number
81A48825
Funding Number(s)
CONTRACT_GRANT: NGL-26-008-065
Distribution Limits
Public
Copyright
Other

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