| Scattered Kuiper belt objects (SKBOs), a type of KBOs which are a group of ice-shaped celestial bodies that were found in the last ten years. Most of KBOs are between 30AU and 50AU, and a small part of them lie outside of the 50AU. But according to speculation, they can reach Oort cloud the furthest. Based on the dynamic character of the KBOs, they are often divided into three types: the classical KBOs (CKBOs), the resonance KBOs (RKBOs) and the scattered KBOs (SKBOs) which were taken up when 1996TL66 was discovered. The characteristics of the SKBOs are that they are far from the sun; they have high eccentricity and high inclination; most of them lie between 50AU and 200 AU and some of them locate farther than 1000AU; the perihelions of them are near 35AU. Because their orbits are doubted to be scattered by the Neptune, so they are called scattered Kuiper belt objects. KBOs are considered to be the debris of primordial solar system and SKBOs are farther than the other two types of KBOs. So the SKBOs may have retained the most primitive information of the solar system. Therefore, the dynamic orbital study of SKBOs can be beneficial to explore the original of these planetary systems and short period comets.Our research mainly includes these parts: (1) using the present observed data of SKBOs, we analyze the character of their orbits and show the rule of the semimajor axis, eccentricity inclination of SKBOs. (2) Using the Hermite algorithms to the N-body model consisted of the Sun, Neptune, Pluto, UB313, and SKBOs, we did numeral simulations of 0.6×108 years clockwise and 0.9×108 years anticlockwise, which include 138 SKBOs of having certain orbits. Our aims are to probe into the initial distribution of SKBOs 0.6×108 years later and 0.9×108 years ago. (3) We did an anticlockwise orbital evolution simulation of 10×108 years long about the 138×7 clone SKBOs, applying the RMVS3 ingtegrator of SWIFT package, comparing the results before, in order to confirm the correction of our conclusion.The main results of this paper are as follows:(1) Most of the SKBOs are quite stable, which maybe always stay in the scattered disk or still stay there more than 10×108 years.(2) A part of SKBOs in the scattered disk once lay aboard the orbit of Neptune near the perihelion are the outer SKBOs which are captured by the large planets. When they move into the interior, the eccentricity decreased.(3) The orbital evolution of SKBOs is related to the initial eccentricity closely.(4) A part of the observed SKBOs presently can move into the interior, some can access into the main Kuiper belt. A part of them are transferred to exterior, some may be scattered out of the solar system. Generally, the initial eccentricities of SKBOs which move into the interior are smaller than that of SKBOs which are transferred to exterior.(5) The inclination changed unobviously in the obital evolution of SKBOs. Generally speaking, the SKBOs are more stable than the classical KBOs.In conclusion, we can find that if the distribution of large planets is changed unobvious in 45×108 years when the solar formed, there are suffice original objects in the scattered disk. They might be the gathered planetesimal from the solar original nebula, and they are the seldom matter of the extended Kuiper belt. A part of the SKBOs might come from the outwards scattered process of the large planet. The number of the SKBOs will increase as the integrator time extends. Some unstable SKBOs are from the remote outside of the solar system which is called Oort cloud. So we can not exclude the existence of the Oort cloud. Furthermore, we should point that the presently observed SKBOs whose perihelions stay near 35AU could not approach to the sun to become the comets in the future 0.6×108 years. We made an anticlockwise simulation in this paper which is different from the past research that assumed the initial conditions of SKBOs. So we have the more scientific and more believable results and basic conclusions.
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