Fallingofftheedge Stories

Sirius is an ordinary Bob from Foahex-over-the-sun. The sun and moon change places each day through a tube in the middle of each Foahex. One day, he walks off the edge of over-the-sun and lands in Foahex-under-the-moon. There he is fought over to be destroyed. Hi guys first attempt at an actual story! Also it is science fiction although the I don't read it, so suggestions would be really helpful. Thank you!!