Solar system. Artwork of the nine planets orbiting the Sun (upper right), as seen from the orbit of Saturn (lower left). The orbits of the planets 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, Saturn, Uranus, Neptune (the outer gas giant planets) and Pluto (a small planet of rock and ice). Apart from Saturn, the outer planets are at top right. The asteroid belt (between Mars and Jupiter) is also seen, and the Milky Way galaxy is in the background.