How many planets are officially recognized in our solar system? The answer is 8. The International Astronomical Union’s 2006 definition recognizes Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune as planets. These worlds orbit the Sun and meet the organization’s criteria for being nearly round and gravitationally dominant in their orbital neighborhoods.
The number became especially memorable after Pluto was reclassified as a dwarf planet. Pluto is round and orbits the Sun, but it has not cleared its orbital neighborhood of other objects, so it does not meet the full planetary definition. The decision reduced the official planet count from the familiar nine to eight.
The eight planets are also grouped by composition. Mercury, Venus, Earth, and Mars are rocky terrestrial planets. Jupiter and Saturn are gas giants, while Uranus and Neptune are ice giants. The solar system also contains dwarf planets, moons, asteroids, comets, and countless smaller bodies.