Mission to Mars complete the sequence to pass a test, and the crew dispatches a robotic rover to reproduce the completed signal. Following the transmission, an opening appears in the side of the structure, which Jim, Terri, and Luke enter, while Phil remains at the repaired Earth return vehicle with orders to launch, with or without them, at the agreed time. The opening seals behind them, disrupting radio communication with Phil, and a three-dimensional projection of the solar system depicts the planet Mars, covered with water, being struck by a large asteroid and rendered uninhabitable. A recreation of a Martian then reveals that
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