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
One of Our Planets Is Missing depart from this galaxy. "One of Our Planets Is Missing" is regarded by some entertainment critics to be "one of the best [shows] that animated [Trek] spin-off has to offer" and "a highly satisfying episode that nicely encapsulates the "Star Trek" philosophy. The show's "animation competently conveys the size and scope of the marauding cloud" which threatens the Federation world of Mantilles. Spock's "mind-meld with the cloud is both logical and satisfying, and Kirk and Spock's wrestling with the need to protect [all] life-forms is intelligent and provocative." Kirk even discusses the rationalisation for his decision "not to kill today"