The Evolution of Worlds/Notes 7
Capture of Satellites
See has recently shown (Astr. Nach. No. 4341–42) that a particle moving through a resisting medium under the attraction of two bodies revolving round one another in circles may eventually be captured by one of them though originally under the domination of both. The argument consists in introducing the effect of a resisting medium upon the motion in the space permitted by Jacobi's integral, following Darwin's examination of this space. In the actual case of nature the effect is much more complicated, and at present is not capable of exact solution for masses other than indefinitely small, even supposing circular orbits for the chief bodies. It may, however, explain the curious relation shown in the arrangement of the direct and retrograde movement of satellites.