1. 宇航员   meteor   astronaut   solar system   satellite   Hint Half-n-half Clue   2. 望远镜   telescope   galaxy   satellite   light years   Half-n-half Clue   3. 彗星   astronaut   comet   universe   astronomer   Half-n-half Clue   4. 天文学家   moon   Sun   Earth   astronomer   Half-n-half Clue   5. 太阳   Sun   atmosphere   astronaut   moon   Half-n-half Clue   6. 大气   telescope   astronaut   galaxy   atmosphere   Half-n-half Clue   7. 地球   meteor   comet   meteorite   Earth   Half-n-half Clue