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
The Planets before Holst's death, and was hailed by astronomers as the ninth planet. Holst, however, expressed no interest in writing a movement for the new planet. He had become disillusioned by the popularity of the suite, believing that it took too much attention away from his other works. In the final broadcast of his Young People's Concerts series in March, 1972, the conductor Leonard Bernstein led the New York Philharmonic through a fairly straight interpretation of the suite, though he discarded the Saturn movement because he thought the theme of old age was irrelevant to a concert for children. The broadcast