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 emotions associated with the influence of the planets on the psyche, not the Roman deities. The idea of the work was suggested to Holst by Clifford Bax, who introduced him to astrology when the two were part of a small group of English artists holidaying in Majorca in the spring of 1913; Holst became quite a devotee of the subject, and would cast his friends' horoscopes for fun. Holst also used Alan Leo's book "What is a Horoscope?" as a springboard for his own ideas, as well as for the subtitles (e.g., "The Bringer of...") for the movements. On 17