In the Courts of the Crimson Kings In the Courts of the Crimson Kings In the Courts of the Crimson Kings is a 2008 alternate history science fiction novel by American writer S. M. Stirling. The story takes place on the planet Mars in an alternate solar system where probes from the United States of America and the Soviet Union find intelligent life and civilizations on both Venus and Mars. The book is heavily influenced by the works of writers such as Edgar Rice Burroughs, Ray Bradbury, and Leigh Brackett, among others. It is a sequel to "The Sky People", which is set on Venus. Stirling later
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