1. 彗星   meteorite   Earth   astronomer   comet   Hint Half-n-half Clue   2. 星   astronaut   star   solar system   outer space   Half-n-half Clue   3. 天文学者   moon   star   light years   astronomer   Half-n-half Clue   4. 衛星   solar system   Sun   meteorite   satellite   Half-n-half Clue   5. 銀河系   satellite   star   astronomer   galaxy   Half-n-half Clue   6. 太陽   Sun   satellite   telescope   atmosphere   Half-n-half Clue   7. 重力   asteroid   planet   Sun   gravity   Half-n-half Clue