Sun Ra and his Solar Arkestra Visits Planet Earth Sun Ra and his Solar Arkestra Visits Planet Earth Sun Ra and his Solar Arkestra Visits Planet Earth is a jazz album by the American musician Sun Ra and his Solar Arkestra. Recorded between late 1956 and 1958, the album was originally released on Ra's own Saturn label in 1966, and has since been reissued on CD by Evidence in 1992. In keeping with many Saturn releases, one side features cuts from the arkestra c.1958, whilst the other side comes from the 1956 sessions originally intended for "Sound of Joy" but still unreleased in 1966. All songs by Sun Ra
Stability of the Solar System essentially the distance from sun to earth). These are now known as the Kirkwood gaps. Some asteroids were later discovered to orbit in these gaps, but their orbits are unstable and they will eventually break out of the resonance due to close encounters with a major planet. Another common form of resonance in the Solar System is spin–orbit resonance, where the period of spin (the time it takes the planet or moon to rotate once about its axis) has a simple numerical relationship with its orbital period. An example is our own Moon, which is in a 1:1 spin–orbit resonance