Solar system. Artwork of the solar system, showing the paths (blue lines) of the nine planets as they orbit around the Sun. The four inner planets are (from inner to outer): Mercury, Venus, Earth and Mars. Around the inner solar system is a broad belt containing thousands of minor planets (asteroids). The five outer planets are (inner to outer): Jupiter (lower right), Saturn (lower left), Uranus (upper centre), Neptune (upper right) and Pluto (far right). The star clouds of our galaxy, the Milky Way, appear as a broad luminous band at upper right.