1. うちゅうひこうし   universe   outer space   asteroid   astronaut   Hint Half-n-half Clue   2. たいき   meteor   universe   solar system   atmosphere   Half-n-half Clue   3. てんぶんがくしゃ   star   meteorite   astronomer   planet   Half-n-half Clue   4. りゅうせい   meteor   asteroid   Earth   Sun   Half-n-half Clue   5. たいようけい   astronomer   solar system   comet   asteroid   Half-n-half Clue   6. うちゅう   orbit   gravity   Sun   universe   Half-n-half Clue   7. じゅうりょく   galaxy   gravity   astronomer   Earth   Half-n-half Clue