Kuiper BeltRegion in the outer solar system beyond Neptune's orbit that contains billions of small, icy planetesimals from the original protoplanetary disc that failed to coalesce into planets. The Kuiper Belt extends from Neptune's orbit at 30 AU to ~55 AU. It is ~20x wider and 20-200x more massive than the object (KBOGenerally, small bodies found in the Kuiper Belt. The largest Kuiper Belt Object (KBO), Eris, is <3000 km in diameter. Image source: http://en.wikipedia.org/wiki/File:EightTNOs.png) that has an orbital periods very similar to that of Pluto. Found in the inner parts of the Kuiper Belt, the orbits of a plutino is stabilized against gravitational perturbations by the 3:2 mean-motion resonance with Neptune, meaning that it orbits the SunOur parent star. The structure of Sun's interior is the result of the hydrostatic equilibrium between gravity and the pressure of the gas. The interior consists of three shells: the core, radiative region, and convective region. Image source: http://eclipse99.nasa.gov/pages/SunActiv.html. The core is the hot, dense central region in which the twice for every three orbits of Neptune.
Some or all content above used with permission from J. H. Wittke.