Summary:
- Figure below shows the relative sizes of the orbits of the planets, asteroid belt, and Kuiper belt.
- In general, the farther away from the Sun, the greater the distance from one planet’s orbit to the next.
- The eight planets orbit the Sun along slightly elliptical paths, with Sun located at one of the foci.
- If the orbital period of a planet is known, then it is possible to determine the planet's distance from the sun.
- This is how astronomers without modern telescopes could determine the distances to other planets within the solar system.