greatest eastern elongation

基本解释

Mercury – the solar system's innermost planet – is at its greatest eastern elongation today.
水星——太阳系最里面的行星—今天是东部最大的延伸。
At greatest eastern elongation, Mercury swings farthest east of the sun, and briefly appears as an evening "star" after sunset.
这是水星是最大程度的在太阳东部的延伸，这是今晚日落后最简短的一次显示。
Don't tarry when looking for Mercury. Even at its greatest eastern elongation, Mercury sets less than 1.5 hours after the sun tonight.
在寻找水星的时候，无须驻足等候。即便处在东大距，日落之后不到1个半小时，水星便下沉了。