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Craters of the Moon. Read Ch. 4 of the text, sections 4.1 through 4.6. William Herschel thought he saw 3 volcanos on the moon in 1787. Arguments circa 1920 in favor of a volcanic origin. Few impact craters known on Earth Meteor crater (Barringer crater) in Arizona.
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Craters of the Moon Read Ch. 4 of the text, sections 4.1 through 4.6
William Herschel thought he saw 3 volcanos on the moon in 1787
Arguments circa 1920 in favor of a volcanic origin • Few impact craters known on Earth • Meteor crater (Barringer crater) in Arizona
Moon craters are mainly round • If impacts came in from all directions, wouldn’t we have more elongated craters?
Impact origin • Championed by G.K. Gilbert and others in the 19th century, but didn’t really take hold until the middle of the 20th
A Michigan native, Ralph Baldwin, helped turn the argument in favor of impacts
Baldwin compared craters produced by explosions on the earth with the craters of the moon • He found that they followed the same trend of diameter versus depth • Impacts produce a generally round explosive crater regardless of direction of impact
Apollo Landings • Lunar rocks mainly breccias – rocks shattered by impacts
If Copernicus were 9-inches across, its depth would be only 1/3 of an inch!
Basins: the Largest impact features Orientale basin