The planets in our solar system don't bounce off each other because they never come into contact with each other. The planets (including the Earth) all orbit the Sun. And the orbital paths all mostly lie on the same plane with each other. But each planet's orbital path lies at a different distance from the Sun. The order of the planets in terms of proximity to the Sun is Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto (although Pluto is no longer officially considered a planet). Even though the orbital paths are not perfect circles, they are far enough apart from each other so there is no danger of planets colliding while orbiting the Sun.