Erosion of the lunar surface by meteor impact
Craters produced by meteorite collision of lunar surface
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Craters produced by meteorite collision of lunar surface
Mechanisms prior to lunar formation are sought to account for the loss of volatiles, the depletion of iron, and the enrichment of plagioclase. Some of the same mechanisms are necessary to account for achondritic, stony-iron, and iron meteorites. Collisions seem marginally capable of providing the heat to accomplish the differentiation into iron, magnesian silicates, and plagioclase. Once this differentiation is accomplished, the subsequent mechanical history should have been sufficient to sort material according to composition in the protolunar circumterrestrial cloud. Effects operating include the correlation of body size with mechanical strength; the lesser ability of the cloud to trap the larger, denser infalling bodies; the more rapid drawing into the Earth of the larger moonlets; and the higher energy orbits for dominantly plagioclase smaller pieces broken off by collision.
Topics addressed include: Cretaceous-Tertiary mass extinctions; geologial indicators for meteorite collisions; carbon dioxide catastrophes; volcanism; climatic changes; geochemistry; mineralogy; fossil records; biospheric traumas; stratigraphy; mathematical models; and ocean dynamics.
Because meteorites are derived from asteroidal objects, the chronology of meteorites give age information on the histories of the asteroidal parents. With a few possible exceptions, the radiometric chronology of less than 4.4 Gyr determined in meteorites can be attributable to collisions among meteorite parent bodies. Three types of collisional chronologies which have been determined are: (1) cosmic ray exposure ages, which generally date the time of the last fragmentation of the parent object when the meteorite is reduced to meter size, and which generally fall over the wide range of 1-1000 Myr; (2) the collisional shock ages shown by many meteorites, which are believed to date the times of major collisions among parent bodies in the asteroid belt in the time interval of 30-700 Myr; and (3) the brecciation ages of several meteorites which are believed to date the times of their collisional formation from regoliths of larger parent bodies over the period of 1.4-4.4 Gyr.
Generalization of Oepik theory of planetary bodies collision to include case where orbits of both colliding bodies are ellipses
Use of the frequency of meteoroid impact and the transport of impact debris to the earth for the interplanetary correlation of geologic time
Fossil glasses produced by impact of meteorites and asteroids with planet earth
Terrestrial and lunar origin of tektites evaluated, emphasizing meteorite impact on the lunar mare
Origin of tektites and impact fragments from the moon
Response of microphone meteorite detectors to impact of high velocity particles
Micrometeorite bombardment initiating discharges and breakdown in ion thrustors
Diameter distribution of young and old craters on lunar Quadrants I and II, noting implication for crater and mare formation
Secular variations of meteoritic and asteroidal fluxes in Earth-Moon region, using lunar craters as records of meteoritic impacts
Scaling laws of penetration of particles traveling at meteoroid velocity, summarizing simulation techniques
Lunar material analysis via alpha particle scattering, using atomic percentage of elements
Self-sealing shields for micrometeorite protection of spacecraft cryogenic propellant tanks
Attitude calculation for meteoroid puncture counting satellite used to predict radiant of puncturing meteoroid
Facilities, equipment, techniques, and experimental procedures for high speed meteoritic impact phenomena