apastronyoudaoicibaDictYouDict[apastron 词源字典]
"The point in the path of a celestial object orbiting a star at which it is farthest from the star", Mid 19th cent.; earliest use found in William H. Smyth (1788–1865), naval officer and surveyor. From apo- + ancient Greek ἄστρον star, after aphelion.[apastron etymology, apastron origin, 英语词源]