Small Solar System body possess some internal structure related to perturbations by the major planets (particularly Jupiter and Neptune, respectively), and have fairly loosely defined boundaries. Other areas of the Solar System also encompass small bodies in smaller concentrations. These include the near-Earth asteroids, centaurs, comets, and scattered disc objects. Small Solar System body A small Solar System body (SSSB) is an object in the Solar System that is neither a planet, a dwarf planet, nor a natural satellite. The term was first defined in 2006 by the International Astronomical Union (IAU) as follows: "All other objects, except satellites, orbiting the Sun shall be
Discovery and exploration of the Solar System yet another planet, "Planet X", must lie beyond Neptune. After his death, his Lowell Observatory conducted a search that ultimately led to Clyde Tombaugh's discovery of Pluto in 1930. Pluto was, however, found to be too small to have disrupted the orbits of the outer planets, and its discovery was therefore coincidental. Like Ceres, it was initially considered to be a planet, but after the discovery of many other similarly sized objects in its vicinity it was reclassified in 2006 as a dwarf planet by the IAU. In 1992, the first evidence of a planetary system other than our own