1. つき   universe   gravity   moon   outer space   Hint Half-n-half Clue   2. すいせい   outer space   astronaut   star   comet   Half-n-half Clue   3. てんぶんがくしゃ   Sun   meteor   astronomer   Earth   Half-n-half Clue   4. こうせい、わくせい   planet   meteorite   astronomer   Sun   Half-n-half Clue   5. りゅうせい   planet   meteor   outer space   galaxy   Half-n-half Clue   6. きどう   orbit   atmosphere   moon   galaxy   Half-n-half Clue   7. いんせき   gravity   satellite   astronaut   meteorite   Half-n-half Clue