Attitude drift toward collinearity of a wayward planet (Q1348217)

The authors study a model planetary system wherein all planets revolve on circular orbits in one plane, except for one planet whose orbital plane has inclination. Using the collinearity principle and a ward spiral, it is shown how a wayward planet would strive towards collinearity with all the other planets to achieve collinearity of the general angular momentum. As an example, using the data for planet Pluto and the equations derived in the present paper, the authors show that in the interval of 100 million years the Pluto's orbital inclination will change by \(1^\circ\), from \(17.2^\circ\) to \(16.2^\circ\).