上じょう合ごう

noun

superior conjunction

Astronomy term: when a planet is on the opposite side of the Sun from Earth. Contrasts with 外合 (inferior conjunction).

See also: 外合

• 金きん星せいが上じょう合ごうの位い置ちにあるとき、地ち球きゅうからは見みえにくい。

  When Venus is at superior conjunction, it is difficult to see from Earth.