昇しょう交こう点てん

noun

ascending node

Astronomical term for the point where an orbit crosses a reference plane from south to north.

• 月つきの昇しょう交こう点てんは約やく18.6年ねん周しゅう期きで移い動どうする。

  The Moon's ascending node moves with a period of about 18.6 years.