outermost orbit

基本解释

New Horizons' trailblazing journey to the solar system's outermost frontier took it past the orbit of Mars today at 6 a. m. EDT , 78 days after the spacecraft launched.
新地平线打响了探索太阳系边疆的第一炮，而在今天美国东部时间早上6点，在发射了78天后它成功跨越了火星轨道。
Its event horizon--theboundary at which nothing, not even light, can escape the monster’s gravitationalpull--is four times as large as the orbit of Neptune,our sun’s outermost planetary satellite.
在它的事件视界，即其边界，没有任何东西可以逃脱这头巨兽的引力，甚至连光也不行。其引力相当于位于我们太阳系最外层行星轨道的海王星的四倍。