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
Battle for Terra won the Grand Prize for Best Animated Feature at the 2008 Ottawa International Animation Festival. Mala (Evan Rachel Wood) and her friend Senn (Justin Long) are young alien creatures who live on Terra, a planet from a star system in the Milky Way. Terra is a peaceful planet of alien creatures who have a rich semi-advanced culture. One day a large, mysterious object blocks the Terrian sun, piquing the Terrians' interest. However, since the Terrian culture bans the development of new technologies, such as telescopes, without the approval of the ruling council, none of the inhabitants are able to get