1. 宇宙飛行士   gravity   astronaut   planet   satellite   Hint Half-n-half Clue   2. 天文学者   comet   astronomer   Sun   meteor   Half-n-half Clue   3. 小惑星   moon   astronomer   asteroid   outer space   Half-n-half Clue   4. 月   planet   atmosphere   moon   light years   Half-n-half Clue   5. 軌道   galaxy   star   orbit   atmosphere   Half-n-half Clue   6. 太陽   astronaut   Sun   solar system   outer space   Half-n-half Clue   7. 大気   outer space   universe   atmosphere   satellite   Half-n-half Clue