1. solar system   suisei   uchuu   tsuki   taiyoukei   Hint Half-n-half Clue   2. astronomer   kidou   suisei   shouwakusei   tenbungakusha   Half-n-half Clue   3. Sun   chikyuu   tenbungakusha   bouenkyou   taiyou   Half-n-half Clue   4. comet   juuryoku   hoshi   bouenkyou   suisei   Half-n-half Clue   5. Earth   chikyuu   inseki   kounen   juuryoku   Half-n-half Clue   6. astronaut   uchuhikoushi   kousei、wakusei   kounen   taiki   Half-n-half Clue   7. light years   tenbungakusha   taiyoukei   kounen   kidou   Half-n-half Clue