e larger hill radius. otherwise the system is defined as being stable. henceforward we state that our planetary system is dynamically stable if no close encounter happens during the age of our solar system， about ±5 gyr. incidentally， this definition may be replaced by one in which an occurrence of any orbital crossing between either of a pair of planets takes place. this is because we know from experience that an orbital crossing is very likely to lead to a close encounter in planetary and protoplanetary systems (yoshinaga， kokubo & makino 1999). of course this statement cannot be simply applied to systems with stable orbital resonances su
对火星轨道变化问题的最后解释(5/49)