Solar system. Artwork of the nine planets orbiting the Sun (yellow). The planetary orbits are shown as blue lines. Distances and sizes are not to scale. In their order from the Sun, the planets are: Mercury, Venus, Earth, Mars (the small, rocky inner planets), Jupiter (lower left), Saturn (lower right), Uranus, Neptune (the outer gas giant planets) and Pluto (a small planet of rock and ice). The latter three are across top. The asteroid belt (between Mars and Jupiter) is also seen, and the Milky Way, the galaxy of which the Sun is a part, runs down the background at right.