1. [zhong;chong] li   gravity   universe   satellite   orbit   Hint Half-n-half Clue   2. gui dao   orbit   outer space   comet   asteroid   Half-n-half Clue   3. wai ceng [kong;kong] [jian;jian]   comet   universe   outer space   asteroid   Half-n-half Clue   4. xing [xi;ji]   meteor   outer space   galaxy   planet   Half-n-half Clue   5. [xing;hang] xing   gravity   moon   planet   meteor   Half-n-half Clue   6. wei xing   satellite   astronaut   Earth   planet   Half-n-half Clue   7. yun [dan;shi]   comet   orbit   astronaut   meteorite   Half-n-half Clue