The axis of rotation of the Earth is tilted, and this can be seen clearly in a globe. Around June 21, the axis points clearly towards the sun. As a result, a large part of the northern hemisphere is illuminated by a strong sun and daytime remains long till the rotation of the Earth causes this area to move away from the direct glare of sunlight. The place, thus, has long hours of sunlight and the days are long. In fact, the sun shines over the North Pole continuously for several weeks without setting even once. This period is known as the ‘polar day’. During Christmas, the axis of the Earth points away from the sun. During these days, the northern hemisphere remains dark for a longer period of time and a ‘polar night’ sets in at the North Pole. On the other hand, the southern sphere enjoys long hours of sun.
