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No. 39: May-Jun 1985

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The Coming Revolution In Planetology

"Current ideas about the moon appear to be mistaken on two fundamental points. First, at least within certain large classes of lunar craters, internal origin (i.e., some form of volcanism) predominates over impact; this result raises questions about the reality of the 'era of violent bombardment.'Second, the origin of tektites by meteoric impact on the earth cannot be reconciled with physical principles and is to be abandoned. The only viable alternative is origin by lunar volcanism, which implies the following: continuance of (rare) explosive lunar volcanism to the present time; existence of silicic lunar volcanism and of small patches of silicic rock at the lunar surface; a body of rock in the lunar interior, probably at great depth, which is closely similar to the earth's mantle and which contains billions of tons of volatiles, probably including hydrogen; and the origin of the moon from the earth after the formation of the earth's core."

"Editor's Note. This article by John O'Keefe puts forth a viewpoint with which most planetologists disagree strongly. On the ground that a fresh airing of the long-standing discussion on lunar volcanism is appropriate, Eos offers this article, untouched by editors or referees, and awaits reply by readers."

O'Keefe's article reviews considerable evidence supporting his two points: for Point One; crater dimensions and frequencies, craters with dark floors, lunar soil constituents; and, for Point Two; tektite analysis. He also remarks that the ages of the terrestrial tektite fields correlate with biological extinctions. This can be explained in terms of lunar volcanism as follows: lunar volcanos expel material violently, some of which escapes the moon's gravitational field and is drawn toward earth. Some falls as tektites; the rest forms a temporary ring around the earth. The ring shadows parts of the earth, causing radical climate changes and, as a consequence, biological extinctions.

(O'Keefe, John A.; "The Coming Revolution in Planetology," Eos, 66:89, 1985.)

Comment. The Editor's Note does not really convey the depth of the antagonism in the controversy about tektite origin.

From Science Frontiers #39, MAY-JUN 1985. 1985-2000 William R. Corliss