Dharti ke dono dharuvon par, North Pole aur South Pole par suraj ki kiranain sal mein sirf ek baar padti hain.
* North Pole: Yahan 21 June ko suraj 24 ghanton tak ubhra rehta hai aur 22 December ko 24 ghanton tak doobta rehta hai.
* South Pole: Yahan 21 December ko suraj 24 ghanton tak ubhra rehta hai aur 22 June ko 24 ghanton tak doobta rehta hai.
Iske alawa, dharti ke dono dharuvon par chhe mahine raat aur chhe mahine din rehta hai.