Sun, Earth and Moon interaction (7TH)

https://www.youtube.com/watch?v=hWkKSkI3gkU Day and night

https://www.youtube.com/watch?v=KUU7IyfR34o Seasons

http://www.sciencekids.co.nz/gamesactivities/earthsunmoon.html Game

https://www.youtube.com/watch?v=suQDwZcnJdg Gravity