Solar system. Diagram showing the orbital paths of the planets in the Solar System. The inset shows the inner Solar System, comprising the terrestrial planets. The scale bar shows one astronomical unit (AU), the distance from the Earth to the Sun, which is around 150 million kilometres. In the main image, the scale bar shows 10 AU. The Sun is seen at upper left in the main image, and at the centre of the inset. The asteroid belt is seen outside the orbit of Mars, followed by the gas giant planets Jupiter, Saturn, Uranus and Neptune. The small rocky planet Pluto is the furthest from the Sun, orbiting at a distance of around 40 AU.