On the Earth, the small circle located at 66.5 degrees south latitude, which is 23.5 degrees latitude north of the Earth's south pole. Below this latitude, the summer Sun never sets, and the winter Sun never rises. See also Arctic Circle
The line of latitude 66°34′S (often taken as 66 Along this line the sun does not set on the day of the summer solstice, about 22 December, and does not rise on the day of the winter solstice, about 21 June.
The parallel of latitude approximately 66°30' south. This parallel marks the northern limit of the area within which for at least one day each year the Sun does not set or rise (about June 21st). It forms the boundary between the South Temperate and South Frigid zones.
parallel of latitude at 66°S
a line of latitude north of the south pole
Parallel of latitude 66°30' S; at this latitude the noon altitude of the Sun is O° on the date of the summer solstice.
The imaginary boundary of the southern polar region
The Antarctic Circle is an imaginary circle at latitude 66°30' S, around the south pole.
The line of latitude on Earth's surface that is 23.5 degrees north of the South Pole. The Antarctic Circle marks the northernmost point in the southern hemisphere that experiences the midnight sun.
A line of latitude at 66° 33' South, when shown as a fixed position on a map, delineates a region, which at the time of the winter solstice (in the Northern Hemisphere), the Sun is above the horizon at local midnight time at all points in this region. (Also the complement of the Tropic of Capricorn, which lies at latitude 23° 27' South).
An imaginary circle on the surface of the earth at 66.5°S lat.or 23.5° north of the South Pole. It marks the southernmost point at which the sun can be seen at the winter solstice (about June 22) and the northernmost point of the southern polar regions at which the midnight sun is visible. .
The Antarctic Circle is one of the five major circles or parallels of latitude that mark maps of the Earth. It is at latitude 66° 33′ 39″ south of the equator (in 2000; like its northern counterpart, the Arctic Circle, the value is currently slowly decreasing over time, pushing the Antarctic Circle southwards with about 15 m per year). For everywhere within the Antarctic Circle, there is at least twenty-four hours of continuous daylight on the summer solstice in December, and at least twenty-four hours of continuous nighttime on the winter solstice in June.