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 Holst taught). It was a comparatively intimate affair, attended by around 250 invited associates, but Holst regarded it as the public premiere, inscribing Boult's copy of the score, "This copy is the property of Adrian Boult who first caused the Planets to shine in public and thereby earned the gratitude of Gustav Holst." A public concert was given in London under the auspices of the Royal Philharmonic Society on 27 February 1919, conducted by Boult. Five of the seven movements were played in the order Mars, Mercury, Saturn, Uranus, and Jupiter. It was Boult's decision not to play all seven