Antarctic Circle

Antarctic Circle, imaginary circle on the surface of the earth at 66 1-2°S lat., i.e., 23 1-2° 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.

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Antarctic Circle

Parallel of latitude approximately 66°30′ south of the Equator that circumscribes the southern frigid zone. It marks the northern limit of the area within which, for one day or more each year, the sun does not set or rise. The length of continuous day or night increases southward from the Antarctic Circle, mounting to six months at the South Pole.

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Antarctic Circle

the imaginary circle around the earth, parallel to the equator, at latitude 66° 32ʹ S; it marks the southernmost point at which the sun appears above the level of the horizon at the winter solstice

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Antarctic Circle [‚ant′ärd·ik ′sər·kəl]

(geodesy)

The parallel of latitude approximately 66°32′ south of the Equator.