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
Five-planet Nice model in 2011 after numerical models indicated that this is more likely to reproduce the current Solar System. The following is a version of the five-planet Nice model that results in a late instability and reproduces a number of aspects of the current Solar System. The early Solar System may have evolved differently, however, with the instability occurring soon after the dissipation of the gas nebula, or with the giant planets beginning in another resonance chain. The Solar System ends its nebula phase with Jupiter, Saturn, and the three ice giants in a 3:2, 3:2, 2:1, 3:2 resonance chain with semi-major