Formation and evolution of the Solar System in turn far closer to the Sun when they formed (most likely in the range of 15–20 AU), and in 50% of simulations ended up opposite locations, with Uranus farther from the Sun than Neptune. According to the Nice model, after the formation of the Solar System, the orbits of all the giant planets continued to change slowly, influenced by their interaction with the large number of remaining planetesimals. After 500–600 million years (about 4 billion years ago) Jupiter and Saturn fell into a 2:1 resonance: Saturn orbited the Sun once for every two Jupiter orbits. This resonance created a
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