Most people measure the day without really thinking about it. Morning arrives, afternoon follows, and eventually the sky begins to darken. The pattern is so familiar that it feels permanent. Yet there are parts of the world where summer interrupts that routine completely. For weeks, and in some cases months, sunset simply does not happen.
The phenomenon is known as the midnight sun. It occurs in regions close to the poles when the Earth's tilt keeps the Sun above the horizon long after it would normally disappear. The effect is strange at first glance. Streets remain bright late into the evening. Mountains cast shadows at midnight. A glance through the window at two in the morning can look remarkably similar to one taken during the afternoon. Across the Arctic and Antarctic regions, several places experience this unusual season each year.
