In our previous work, we investigated the orbital dynamics of Asteroid 1934 CT (or 1989 AC or 4179 Toutatis) from epoch 2012-Jul-24 (JDE2456132.5) using the Mercury program package. Asteroid 4179 Toutatis has an Earth and Mars crossing orbit with semimajor axis a = 2.5292 AU and eccentricity e = 0.6294, and therefore the perihelion distance is q = 0.9373 AU and the aphelion distance is Q = 4.1211 AU. After more than 300,000 years, asteroid 4179 Toutatis will escape from the Solar System, but during this time, it will have close-encounters with other planets from Venus to Uranus. As a continuation of this project, we investigated its energy changes in each close encounter. We also determine the energy of this asteroid when it escapes from the Solar System. The result is that during its orbital evolution, the energy of this asteroid changes and gives us negative, zero and positive values.

소백산 천문대의 0.6m 광학망원경과 2K CCD 카메라를 이용하여 소행성 55 Pandora에 대한 R 필터 시계열 측광관측을 수행하였다. 관측으로부터 소행성의 자전 주기(P=4.h8168)와 진폭(δR=0.281±0.001란 구하였고, Amplitude-Magnitude 방법을 이용하여, 소행성 55 Pandora의 자전축 방향 λp((o)=342, βp(o)=64와 세 축의 비는 a/b=1.27, b/c=1.31인 형태로 자전하고 있음을 알아내었다.

In this paper it is explained how most of asteroids can avoid very close approach to Jupiter, to the earth for earth orbit crossing asteroids, and to Neptune for Kuiper-belt asteroids by mechanisms which work also for Neptune-Pluto system. In fact the mutual distance of the planets cannot become very small as the critical argument librates around 180° because of 2:3 mean motion resonance and the argument of perihelion of Pluto librates around 90°. And it is found that among nearly 40 Kuiper-belt asteroids discovered in recent years 40% have orbits similar to Pluto. For main-belt asteroids the distribution with respect to the semi-major axes has peculiar characteristics and the author tries to explain how their peaks and gaps are created. It is also found that 30% of 80 earth orbit crossing asteroids which have minimum perihelion distances less than 1.04AU have no chance to collide with the earth. Still 30% of them have a few probability to collide with the earth as they have dynamical characteristics of short-periodic comets.