Simulations Of The Original Distribution Of KBOs

Kuiper Belt Objects, or KBOs, is a group of ice-shaped celestial bodies which is newly discovered out of the Neptune and around the sun-operation. Most of KBOs located 30 to 50 AU from the sun in a circular band. Generally, they are considered to be the wreckages of the initial formation of the solar system, and the study of them may have many most primitive information of the early solar system. This will not only promote our understandings about the formation and evolution of the solar system but also provide important reference value on the discovery of the extrasolar planetary systems and the theoretical research.The paper made a reverse numerical simulation on the observed KBOs with reliable orbital element on the basis of the celestial mechanics theory of the N-body problem. This is to say, we used the observed orbital element of KBOs, deducing their previous tracking operations conversely, in order to determine their orbital characteristics in the early solar system.The research of this paper can be divided into three parts:(1) We did an orbital evolution simulation of 1×109 years long about the current observed and orbit-affirmed 551 KBOs, applying the RMVS3 integrator of the SWIFT package in the model of the N-body problem of the sun, the terrestrial planet, Jupiter, Saturn, Neptune, Pluto,UB313 and KBOs. The step is in an"anti-time"direction,in order to seek the original orbit distribution. of KBOs 1×109 years ago.(2) On the basis of (1), we took 2 random numerical values of theω, ? and M about the 551 KBOs except Pluto and UB313, then, we got 1098 virtual particles. The purpose of repeating the experiment (1) is to test the accuracy of the results.(3) We randomly selected a small portion of KBOs which went into the Kuiper Belt from the distant outer edge of the solar system. We made a time tracking analysis on them on the purpose of getting a detailed understanding of their orbit evolution process.We made a random sample of the transgressed KBOs and tracked them. We hope to find out how they enter into the Kuiper Belt from the external solar systemThe main conclusions of this paper are as follows:(1) A part of KBOs may be in formation of the original nebula, and the other part came from a more distant places far from the sun. The studies on the track of the evolution of the objects shows that the vast majority of objects in the vicinity of the Neptune 3:2 resonance come from 50 AU from outside the region, and most of the classical KBOs is originally in the interval from 35 to 50 AU.(2) Part of the KBOs come from the high orbital inclination and eccentricity of the larger distant objects. In the evolution of entering Kuiper Belt, most of the orbital eccentricity and inclination getting smaller, while the one entering the resonance belts is generally getting bigger.(3) The track we made on a part of the transgressed KBOs shows their wonderful running states before the capture and the complex running trajectory after capture,which discovered there may be mutual relations between extrasolar planets,comets and KBOs.The innovation of this paper is as follows:In the past, many researchers used the numerical method to simulate the formation of Kuiper Belt. They all assumed a series of initial conditions trying to get the orbit distribution of the observed objects by changing some adjustable parameters. This approach, however, is difficult to obtain the desired results and workload. We have innovated a solution. We made a"reverse simulation"with the current observational data, which can work out the initial formation of the solar system to find out the "real" original distribution of KBOs.The regret of this paper is that the impact of the major planets haven't been considered. At the same time, the objects once located in the Kuiper Belt and later escaped, as their information is impossible to be found, they can't be tracked. This might make some evolution information can't be reproduced.