Solar System showing innermost four planets (Mercury, Venus, Earth, and Mars) orbiting our sun. The simulation begins with all of the planets lined up at their maximum distances from the sun (aphelion). As they are released, so they are attracted to the sun and describe their various orbits. This arrangement allows you to compare their distances and orbits in a simple way. In reality, the planets are not aligned in this way and their orbits are at angles to each other. The planets are shown at their correct relative sizes (i.e. compared to each other) and their correct relative distances. Their relative years (orbital periods) are also about right. The sun is shrunk down compared to the planets so that it doesn't swallow the innermost planets. In reality, the planets (and even the sun) are very tiny compared with the orbital distances. If you look carefully, you can see that Mercury speeds up as it gets closer to the Sun.