Bow shocks in astrophysics magnetized, such as Jupiter or Saturn. Earth's bow shock is about thick and located about from the planet. Bow shocks form at comets as a result of the interaction between the solar wind and the cometary ionosphere. Far away from the Sun, a comet is an icy boulder without an atmosphere. As it approaches the Sun, the heat of the sunlight causes gas to be released from the cometary nucleus, creating an atmosphere called a coma. The coma is partially ionized by the sunlight, and when the solar wind passes through this ion coma, the bow shock appears. The first
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