Jupiter has always been fascinating to astronomers and non-astronomers alike. For Hector Berlioz, Jupiter was the bringer of joviality in his composition "The Planets."  But some solar system theorists may not feel so jovial when considering a recent theory about the likelihood of Jupiter's existence.  A group of astronomers have found evidence that giant gas planets like Jupiter may be rare in other solar systems, and this may say something important about the origin of our solar system.

The author of Paper 57 in The Urantia Book informs us that our solar system formed from material pulled out of our sun by a passing dark giant of space, Angona. (657.) This theory of origin, known to astronomers as the catastrophic or dualistic theory, was proposed independently by Thomas Crowder Chamberlin and Forest Ray Moulton in the early part of this century.¹ Another source² says that the theory was first suggested early in this century by astronomer Sir James Jean and geophysicist Sir Harold Jefferies. The astronomic community eventually rejected this theory for several reasons, one being that such an encounter would be quite rare. In fact, we are told on page 466 that most planets did not have such an origin.

The Encyclopedia Britannica gives an additional reason for rejection of the catastrophic theory: "....acquired a more mature understanding of the behavior of gases under astrophysical conditions.  This perspective led to the realization that hot gases stripped from a stellar atmosphere would simply dissipate in space; they would not condense to form planets."¹  It seems to me that the idea in The Urantia Book sounds more reasonable; some of the material pulled out would fall back into the sun, some would be captured by the body passing by the sun, but some material would stay in orbit. Perhaps this orbiting material formed a disc around our sun, and  from this disc the planets of our solar system formed.

There was another problem found with the catastrophic theory, namely the distribution of angular momentum in the solar system. Angular momentum is a measure of the speed of rotation of a body around a center and it's distance from that center of rotation. Though the sun has 99.9% of the solar system's mass, it has less than 0.5% of its angular momentum. Jupiter, with only a fraction of a percent of the mass in the solar system has about 99% of the angular momentum of the solar system. This situation would not be expected if the solar system had a catastrophic origin. Significantly however, this unexpected distribution of angular momentum is also a problem for the other major theory of planetary formation, the nebular or monistic theory.

In the eighteenth century, the philosopher Immanual Kant proposed that our planetary system coalesced from a cloud or nebula of dispersed particles. About twenty years later, the mathematician LaPlace proposed that a cloud of dust and gases around a sun would form into rings from which planets would coalesce.¹

In fact, this idea of ring formation is mentioned in The Urantia Book on Page 170. The author does not specifically say that the rings form into planets, but the entry is under the heading "The Origin of Space Bodies," so that planetary formation from the rings is intimated. Astronomers are now finding many young stars with discs of dust and gas around them, and this tends to support the idea that planets form from such rings. But in the case of our solar system, the nebular hypothesis has problems other than that of the distribution of angular momentum.

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One of the unusual features found in our system is retrograde motion (or more correctly, retrograde rotation) of two planets, and some moons of several planets. If a planetary system formed from a uniform disc of material, we would expect the planets and their satellites to all lie in the same plane and rotate in the same direction. If a planet rotates in the opposite direction from the others, that phenomenon is an example of a type of retrograde motion. There are two planets, Venus and Uranus, that exhibit retrograde rotation in our solar system.

Astronomers have not found an explanation to account for this retrograde motion that is satisfactory to everyone. The problem of retrograde motion in our solar system is mentioned on Page 657 where the Life Carrier author tells us:

"Retrograde motion in any astronomic system is always accidental and always appears as a result of the collisional impact of foreign space bodies. Such collisions may not always produce retrograde motion, but no retrograde ever appears except in a system containing masses which have diverse origins."
According to the author, the masses which caused the retrograde motion were captured by our sun from the passing Angona system. And in addition to the problems already mentioned, the nebular hypothesis now has a Jupiter problem.

[Detailed studies of isotope anomolies in meteorites have provided evidence that the solar nebular was contaminated very early in its history by one or more injections of material from sources external to the solar system. (from Dodds, R.T., "Thunderstones and Shooting Stars." Harvard University Press, 1986)]

A recent article in Science News³ reported that a team from MIT examined 20 nearby, sunlike stars one to ten million years old and reported that even these very young stars did not have enough molecular hydrogen in their vicinity to form a planet the size of Jupiter. The researchers conclude that either a planet like Jupiter would have to form very quickly before the hydrogen was lost, or more likely there is only a small chance of such planets forming in the first place. If, on the other hand, material were pulled out from our sun as claimed in The Urantia Book, there would be plenty of material to form the two gas giant planets, Jupiter and Saturn.

The catastrophic origin hypothesis/Angona theory  may still have more strikes against it than the nebular hypothesis, but it looks like the score is beginning to even up. Perhaps early in the third millennial innings astronomers will resurrect the catastrophic hypothesis and come to the same conclusion as the author of Paper 57.  And 2001 isn't so far off, is it?

Dick Bain, USA.

References:

(1) Encyclopedia Britannica Macropedia, 1993
(2) Preston Cloud  (1978).  "Cosmos, Earth and Man,"  (Yale University Press)
(3) "The Importance of Being Jupiter", Science News.