Astronomical Topics

Abstract

Meteoric Hypothesis for the Origin of the Solar System.—The Abbé Moreux contributes articles on cosmogony to Scientia for September and October. Instead of invoking the approach of another star to the sun, he supposes the sun to have traversed a region of space full of dust or meteoric matter, such as are indicated by the dark ‘Horse's Head’ in Orion and a number of similar dark patches. The orbits of such particles about the sun would in general be hyperbolic, but he suggests that by collisions and other mutual interference a considerable part of the matter might be captured by the sun. He traces its subsequent behaviour in some detail, and attempts an explanation of Bode's law of planetary distances. He notes that the planes of the giant planets are alternately on opposite sides of the invariable plane of the system; he draws an argument from this in support of his system. But the planes are in a state of constant change, and it would seem that proof is required that the relation now existing is permanent before any cosmogonic argument can be drawn from it. In his discussion of Neptune's system he assumes that Neptune's rotation is retrograde, like the motion of the satellite. The observations of J. H. Moore and D. H. Menzel at the Lick Observatory in 1928 showed that the rotation is direct. In such a difficult subject as cosmogony, it is well that all possible suggestions should be examined. It is unlikely that any one of the suggested systems is completely true.