greatest eastern elongation

常见例句

Mercury – the solar system's innermost planet – is at its greatest eastern elongation today.
水星——太陽系最裡麪的行星—今天是東部最大的延伸。
At greatest eastern elongation, Mercury swings farthest east of the sun, and briefly appears as an evening "star" after sunset.
這是水星是最大程度的在太陽東部的延伸，這是今晚日落後最簡短的一次顯示。
Don't tarry when looking for Mercury. Even at its greatest eastern elongation, Mercury sets less than 1.5 hours after the sun tonight.
在尋找水星的時候，無須駐足等候。即便処在東大距，日落之後不到1個半小時，水星便下沉了。