solar system to scaleThe eight planets of the solar system and Pluto, in a montage of images scaled to show the approximate sizes of the bodies relative to one another. Outward from the Sun, which is represented to scale by the yellow segment at the extreme left, are the four rocky terrestrial planets (Mercury, Venus, Earth, and Mars), the four hydrogen-rich giant planets (Jupiter, Saturn, Uranus, and Neptune), and icy, comparatively tiny Pluto.
solar system, The Sun, its eight major planets, the dwarf planets and small bodies, and interplanetary dust and gas under the Sun’s gravitational control. Another component of the solar system is the solar wind. The Sun contains more than 99% of the mass of the solar system; most of the rest is distributed among the planets, with Jupiter containing about 70%. According to the prevailing theory, the solar system originated from the solar nebula. See also asteroid; Centaur object; Ceres; comet; Earth; Eris; Jupiter; Kuiper belt; Mars; Mercury; meteorite; Neptune; Oort cloud; Pluto; Saturn; Uranus; Venus.