(Astronomy)the point in the orbit of a planet, asteroid, or comet at which it is furthest from the sun (天文)远日点。 perihelion 的反义词 Mars is at aphelion. 火星处在远日点。
语源
mid 17th cent.: alteration of modern Latin aphelium (by substitution of the Greek inflection -on), from Greek aph' hēlion 'from the sun'