1. yu hang [yuan]   Earth   atmosphere   astronaut   meteor   Hint Half-n-half Clue   2. [zhong;chong] li   meteor   gravity   asteroid   universe   Half-n-half Clue   3. [xing;hang] xing   comet   gravity   moon   planet   Half-n-half Clue   4. wang yuan jing   telescope   comet   Earth   star   Half-n-half Clue   5. guang nian   astronomer   moon   light years   outer space   Half-n-half Clue   6. fei xing   Sun   meteor   universe   solar system   Half-n-half Clue   7. yun [dan;shi]   moon   meteorite   star   galaxy   Half-n-half Clue