The polar night occurs when the night lasts for more than 24 hours. This occurs only inside the polar circles. The conflicting occurrence, the polar day, or midnight sun, occur when the Sun stay on top of the prospect for more than 24 hours. “Night” is unspoken as the middle of the Sun being underneath a free horizon. Since the ambiance bends the rays of the Sun, the glacial day is longer the polar night, and the region that is exaggerated by polar night is rather smaller than the region of midnight sun. The polar circle is situated at a leeway between these two areas, at the latitude of about 66.5 degrees. In the the majority northern city of Sweden, Kiruna, or the 67°51’N, the polar night last for approximately 28 twenty-four-hour period as the midnight sun lasts approximately 50 twenty-four-hour of period.