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No. 70: Jul-Aug 1990

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The Oort Cloud of comets hovering at the far frontiers of the solar system is, as we know from SF#57, not without its anomalies. Here, let us assume that it really does exist, even though we cannot see it.

From a new book by I. Asimov (title below), we learn that this remote haze of icy fluff, the Oort Cloud, may really have about 90% of the angular momentum of the entire solar system. It was already sufficiently anomalous to discover that the planets possess fifty times the angular momentum of the much more massive sun. (See ABB3 in The Sun and Solar System Debris.) Astronomers have been attempting for years to explain this 50:1 split. Now, with the Oort Cloud apparently having ten times the angular momentum of the planets, the situation is much worse. According to Asimov, the solar-system angular momentum is split as follows:

Oort Cloud 90% All of the planets 9.8% The sun 0.2%

The total mass of the Oort Cloud is estimated to be roughly that of Saturn.

The recent flyby of Halley's Comet created this dilemma. It was discovered that Halley was a chunk containing 140 cubic miles of ice - much larger than anticipated for this "typical" comet. If the estimated 2 trillion comets are, on the average, Halley's size, the Oort Cloud is a thousand times more massive than previously thought. This, combined with estimates of Oort Cloud distance and angular velocity leads to the almost ridiculous distribution of solar-system angular momentum tabulated above. This will keep the theorists busy for a while.

(Asimov, Isaac; Frontiers: New Discoveries about Man and His Planet, Outer Space and the Universe, New York, 1989, p. 270. Cr. C. Ginenthal)

Comment. Perhaps the Oort Cloud isn't there after all. Or, if it is, it isn't rotating as rapidly as thought. In any case, the accepted theory of solarsystem formation is in trouble.

Reference. Details concerning our catalog The Sun and Solar System Debris may be found here.

From Science Frontiers #70, JUL-AUG 1990. 1990-2000 William R. Corliss