内ない合ごう

noun

inferior conjunction

Astronomy term for when an inner planet (Mercury or Venus) passes between the Earth and the Sun. Contrasts with 外合 (superior conjunction).

See also: 外合

• 金きん星せいが内ない合ごうを迎むかえると、地ち球きゅうからは見みえにくくなる。

  When Venus reaches inferior conjunction, it becomes difficult to see from Earth.