The solar system consists of the Sun and eight planets. The Sun is a huge luminous body that is the central object and primary source of energy. The planets range in size from Mercury, the smallest planet closest to the Sun, to Jupiter, the largest planet. Features of the planets include Mercury's extreme temperatures, Venus' dense atmosphere, Earth's water and life, Mars' thin atmosphere, Jupiter's massive size, Saturn's iconic rings, Uranus' gaseous composition, and Neptune's strong winds.