Stability of the Solar System that keeps the far side of the Moon away from the Earth. Mercury is in a 3:2 spin–orbit resonance. The planets' orbits are chaotic over longer timescales, such that the whole Solar System possesses a Lyapunov time in the range of 2–230 million years. In all cases this means that the position of a planet along its orbit ultimately becomes impossible to predict with any certainty (so, for example, the timing of winter and summer become uncertain), but in some cases the orbits themselves may change dramatically. Such chaos manifests most strongly as changes in eccentricity, with some planets' orbits
The Planets the suite and that the movements on either side are in mirror images. Thus Mars involves motion and Neptune is static; Venus is sublime while Uranus is vulgar, and Mercury is light and "scherzando" while Saturn is heavy and plodding. This hypothesis is lent credence by the fact that the two outer movements, Mars and Neptune, are both written in rather unusual quintuple meter. Holst suffered neuritis in his right arm, which caused him to seek help from several amanuenses in scoring "The Planets". This is clear from the number of different hands apparent in the full score. Neptune was