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Arctic Circle,imaginary circle on the surface of the earth at 66 1-2°N latitude, i.e., 23 1-2° south of the North Pole. It marks the northernmost point at which the sun can be seen at the winter solsticesolstice
[Lat.,=sun stands still], in astronomy, either of the two points on the ecliptic that lie midway between the equinoxes (separated from them by an angular distance of 90°).
..... Click the link for more information. (about Dec. 22) and the southernmost point of the northern polar regions at which the midnight sunmidnight sun,
phenomenon in which the sun remains visible in the sky continuously for 24 hr or longer, occurring only in the polar regions. The midnight sun is due to the fact that the plane of the earth's equator is tilted about 23 1-2° to the plane of the ecliptic (the
..... Click the link for more information. is visible.
Arctic Circle[¦ärd·ik ′sər·kəl]
The parallel of latitude 66°32′N (often taken as 66½°N).
the imaginary circle round the earth, parallel to the equator, at latitude 66° 32ʹ N; it marks the northernmost point at which the sun appears above the level of the horizon on the winter solstice