Where does the sky end?
Where is the border between sky and space? That's what 5-year-old Matthias of Durham, New Hampshire wants to know. Alesandra, 3 of Bella Vista, Arkansas wants to know why we can't hold air. In this…
Where is the border between sky and space? That's what 5-year-old Matthias of Durham, New Hampshire wants to know. Alesandra, 3 of Bella Vista, Arkansas wants to know why we can't hold air. In this…