Midnight sun
Midnight sun is a phenomenon that exists north of the Arctic Circle and south of the Antarctic Circle, where the Sun won't set at all and remains above the horizon at solar midnight. It means that the sun, on parts of the year, is visible the whole night long. The sun above the horizon at midnight in the Arctic or Antarctic summer.
There are no people living permanently south of the Antarctic Circle (like Antarctica), but in Alaska, Canada, Norway, Greenland, Sweden, Finland, Russia, and some other countries north of the Arctic Circle, it is possible to watch the Midnight sun in the summer.
The opposite of the Midnight sun is the Polar night, where the Sun won't rise at all and remains below the horizon even at solar noon.
Midnight Sun Media
Midnight sun at the North Cape on the island of Magerøya in Norway
Multiple exposure of midnight sun on Lake Ozhogino in Yakutia, Russia
Embankment of the Neva river in Saint Petersburg, 23:30 local time, 22 June 2013
Map showing the dates of midnight sun at various latitudes (left) and the total number of nights
At Earth's poles the Sun appears at the horizon only and all day around equinox, marking the change between the half year long polar night and polar day. The picture shows the South Pole right before March equinox, with the Sun appearing through refraction despite being still below the horizon.
