母ぼ星せい

noun

homeworld; home planet; mother planet

Used in science fiction or space contexts to refer to the planet of origin for a species or individual.

• 宇う宙ちゅう飛ひ行こう士しは長ながい旅たびの後あと、母ぼ星せいに帰き還かんした。

  The astronaut returned to their home planet after a long journey.