Twilight: Civil, nautical, astronomical; southernmost / northernmost latitudes.
The extreme southernmost / northernmost latitudes in the Northern / Southern Hemispheres that Civil, Nautical, and Astronomical Twilight can last through local solar midnight or twilight all night, at the Northern / Southern Hemisphere's solstices, also the Arctic, and Antarctic latitudes for these dates and times; calculated using the PHP Science Labs Website, Obliquity of the Ecliptic and Nutation in Obliquity (using IAU 2000B nutation series); i.e true obliquity of the ecliptic, as used by the National Land Survey of Finland, Finnish Geodetic Institute, and the GIT Barents website:
2013 Northern Hemisphere, summer solstice:
Arctic / Antarctic Circle 66° 33’ 52.049” N / S
Civil twilight 60° 33’ 52.049” N
Nautical twilight 54° 33’ 52.049” N
Astronomical twilight 48° 33’ 52.049” N
2013 Southern Hemisphere, summer solstice:
Antarctic / Arctic Circle 66° 33’ 53.249” S / N
Civil twilight 60° 33’ 53.249” S
Nautical twilight 54° 33’ 53.249” S
Astronomical twilight 48° 33' 53.249” S
2014 Northern Hemisphere, summer solstice:
Arctic / Antarctic Circle 66° 33’ 54.232” N / S
Civil twilight 60° 33’ 54.232” N
Nautical twilight 54° 33’ 54.232” N
Astronomical twilight 48° 33’ 54.232” N
2014 Southern Hemisphere, summer solstice:
Antarctic / Arctic Circle 66° 33’ 55.178” S / N
Civil twilight 60° 33’ 55.178” S
Nautical twilight 54° 33’ 55.178” S
Astronomical twilight 48° 33’ 55.178” S
2015 Northern Hemisphere, summer solstice:
Arctic / Arctic Circle 66° 33’ 55.571” N / S
Civil twilight 60° 33’ 55.571” N
Nautical twilight 54° 33’ 55.571” N
Astronomical twilight 48° 33’ 55.571” N
2015 Southern Hemisphere, summer solstice:
Antarctic / Arctic Circle 66° 33’ 55.890” S / N
Civil twilight 60° 33’ 55.890” S
Nautical twilight 54° 33’ 55.890” S
Astronomical twilight 48° 33’ 55.890” S
2016 Northern Hemisphere, summer solstice: Circumference or length:
Arctic / Antarctic Circle 66° 33’ 55.941” N / S 15,982.926417462362 km or 9,931.330043460169 miles.
Civil twilight 60° 33’ 55.941” N 19,744.162762640396 km or 12,268.453955549836 miles.
Nautical twilight 54° 33’ 55.941” N 23,286.147101212778 km or 14,469.340986894522 miles.
Astronomical twilight 48° 33’ 55.941” N 26,570.194478309322 km or 16,509.953420964891miles.
2016 Southern Hemisphere, summer solstice: Circumference or length:
Antarctic / Arctic Circle 66° 33’ 55.524” S / N 15,983.000884214218 km or 9,931.376314954552 miles.
Civil twilight 60° 33’ 55.524” S 19,744.233388049778 km or 12,268.497840144666 miles.
Nautical twilight 54° 33’ 55.524” S 23,286.213111060426 km or 14,469.382003512255 miles.
Astronomical twilight 48° 33’ 55.524” S 26,570.255154469880 km or 16,509.991123383118 miles.
2017 Northern Hemisphere, summer solstice: Circumference or length:
Arctic / Antarctic Circle 66° 33’ 55.078” N / S 15,983.081 km or 9,931.426 international miles.
Civil twilight 60° 33’ 55.078” N 19,744.309 km or 12,268.545 international miles.
Nautical twilight 54° 33’ 55.078” N 23,286.284 km or 14,469.426 international miles.
Astronomical twilight 48° 33’ 55.078” N 26,570.320 km or 16,510.031 international miles.
2017 Southern Hemisphere, summer solstice: Circumference or length:
Antarctic / Arctic Circle 66° 33’ 54.374” S / N 15,983.206 km or 9,931.504 international miles.
Civil twilight 60° 33’ 54.374” S 19,744.428 km or 12,268.619 international miles.
Nautical twilight 54° 33’ 54.374” S 23,286.395 km or 14,469.495 international miles.
Astronomical twilight 48° 33’ 54.374” S 26,570.422 km or 16,510.095 international miles.
2018 Northern Hemisphere, summer solstice: Circumference or length:
Arctic / Antarctic Circle 66° 33’ 53.296” N / S 15,983.399 km or 9,931.624 international miles.
Civil Twilight 60° 33’ 53.296” N / S 19,744.611 km or 12,268.732 international miles.
Nautical Twilight 54° 33’ 53.296” N / S 23,286.566 km or 14,469.601 international miles.
Astronomical Twilight 48° 33’ 53.296” N / S 26,570.579 km or 16,510.192 international miles.
2018 Southern Hemisphere, summer solstice: Circumference or length:
Antarctic / Arctic Circle 66° 33’ 52.385” S / N 15,983.561 km or 9,931.724 international miles.
Civil twilight 60° 33’ 52.385” S 19,744.765 km or 12,268.828 international miles.
Nautical twilight 54° 33’ 52.385” S 23,286.710 km or 14,469.691 international miles.
Astronomical twilight 48° 33’ 52.385” S 26,570.712 km or 16,510.275 international miles.
2019 Northern Hemisphere, summer solstice: Circumference or length:
Arctic / Antarctic Circle 66° 33’ 51.083” N / S 15,983.794 km or 9,931.869 international miles.
Civil twilight 60° 33’ 51.083” N 19,744.986 km or 12,268.965 international miles.
Nautical twilight 54° 33’ 51.083” N 23,286.916 km or 14,469.819 international miles.
Astronomical twilight 48° 33’ 51.083” N 26,570.901 km or 16,510.392 international miles.
Area, calculated in the WGS84 ellipsoid:
Arctic / Antarctic 21,204,911.158404 km² or 8,187,261.969961 miles².
Civil Twilight and above i.e. 60° 33’ 51.083” N to 66° 33’ 51.083” N 11,958,971.290329 km² or 4,617,384.629143 miles².
Nautical Twilight and above i.e. 54° 33’ 51.083” N to 60° 33’ 51.083” N 14,390,453.065933 km² or 5,556,184.991160 miles².
Astronomical Twilight and above i.e. 48° 33’ 51.083” N to 54° 33’ 51.083” N 16,656,552.760405 km² or 6,431,130.974669 miles².
2019 Southern Hemisphere, summer solstice: Circumference or length:
Antarctic / Arctic Circle 66° 33’ 49.748” S / N 15,984.032 km or 9,932.017 international miles.
Civil twilight 60° 33’ 49.748” S 19,745,212 km or 12,269.106 international miles.
Nautical twilight 54° 33’ 49.748” S 23,287.127 km or 14,469.950 international miles.
Astronomical twilight 48° 33’ 49.748” S 26,571.096 km or 16,510.514 international miles.
2020 Northern Hemisphere, summer solstice: Circumference or length:
Arctic / Antarctic Circle 66° 33’ 48.571” N / S 15,984.243 km or 9,932.148 international miles.
Civil twilight 60° 33’ 48.571” N 19,745.411 km or 12,269.230 international miles.
Nautical twilight 54° 33’ 48.571” N 23,287.314 km or 14,470.066 international miles.
Astronomical twilight 48° 33’ 48.571” N 26,571.267 km or 16,510.620 international miles.
Area, calculated in the WGS84 ellipsoid:
Above Arctic / Antarctic Circle 21,206,154.924556 square km or 8,187,742.190757 square miles.
Civil Twilight and above to Arctic Circle, i.e. 60° 33’ 51.083” N to 66° 33’ 51.083” N 11,959,262.667275 square km or or 4,617,497.130411 square miles.
Nautical Twilight and above to lowest latitude for Civil Twilight, i.e. 54° 33’ 51.083” N to 60° 33’ 51.083” 14,390,726.713755 square km or 5,556,290.647175 square miles.
Astronomical Twilight and above to lowest latitude for Nautical Twilight, i.e. 48° 33’ 51.083” N to 54° 33’ 51.083” N 16,656,805.720382 square km or 6,431,228.643062 square miles.
2020 Southern Hemisphere, summer solstice: Circumference or length:
Antarctic / Arctic Circle 66° 33’ 47.077” S / N 15,984.509 km or 9,932.313 international miles.
Civil twilight 60° 33’ 47.077” S 19,745.664 km or 12,269.387 international miles.
Nautical twilight 54° 33’ 47.077” S 23,287.550 km or 14,470.213 international miles.
Astronomical twilight 48° 33’ 47.077” S 26,571.484 km or 16,510.755 international miles.
Distances personally calculated in the WGS84 ellipsoid, using Charles Karney's Online rhumb line calculations using the RhumbSolve utility: "RhumbSolve is accurate to about 15 nanometers (for the WGS84 ellipsoid)" or 0.000015 of a millimetre/millimeter or 0.00000059 of an inch. In emails to me from Charles Karney: "The accuracy of 15 nanometers that I quote is for paths up to half-way round the earth." "The accuracy for the Airy" [1830] "ellipsoid will be (very nearly) the same as for the WGS84 ellipsoid because the parameters are roughly the same." On RhumbSolve online: "RhumbSolve performs rhumb line calculations". "The path with a constant heading between two points on the ellipsoid at (lat1, lon1) and (lat2, lon2) is called the rhumb line (or loxodrome)". "NOTE: the rhumb line is not the shortest path between two points; that is the geodesic and it is calculated by GeodSolve."
Areas personally calculated in the WGS84 ellipsoid, using Charles Karney's geodesic polygon calculations using the Planimeter utility. "The result for the area is accurate to about 0.1 m² per vertex."
See also: http://www.gandraxa.com/length_of_day.xml
2013 Northern Hemisphere, summer solstice:
Arctic / Antarctic Circle 66° 33’ 52.049” N / S
Civil twilight 60° 33’ 52.049” N
Nautical twilight 54° 33’ 52.049” N
Astronomical twilight 48° 33’ 52.049” N
2013 Southern Hemisphere, summer solstice:
Antarctic / Arctic Circle 66° 33’ 53.249” S / N
Civil twilight 60° 33’ 53.249” S
Nautical twilight 54° 33’ 53.249” S
Astronomical twilight 48° 33' 53.249” S
2014 Northern Hemisphere, summer solstice:
Arctic / Antarctic Circle 66° 33’ 54.232” N / S
Civil twilight 60° 33’ 54.232” N
Nautical twilight 54° 33’ 54.232” N
Astronomical twilight 48° 33’ 54.232” N
2014 Southern Hemisphere, summer solstice:
Antarctic / Arctic Circle 66° 33’ 55.178” S / N
Civil twilight 60° 33’ 55.178” S
Nautical twilight 54° 33’ 55.178” S
Astronomical twilight 48° 33’ 55.178” S
2015 Northern Hemisphere, summer solstice:
Arctic / Arctic Circle 66° 33’ 55.571” N / S
Civil twilight 60° 33’ 55.571” N
Nautical twilight 54° 33’ 55.571” N
Astronomical twilight 48° 33’ 55.571” N
2015 Southern Hemisphere, summer solstice:
Antarctic / Arctic Circle 66° 33’ 55.890” S / N
Civil twilight 60° 33’ 55.890” S
Nautical twilight 54° 33’ 55.890” S
Astronomical twilight 48° 33’ 55.890” S
2016 Northern Hemisphere, summer solstice: Circumference or length:
Arctic / Antarctic Circle 66° 33’ 55.941” N / S 15,982.926417462362 km or 9,931.330043460169 miles.
Civil twilight 60° 33’ 55.941” N 19,744.162762640396 km or 12,268.453955549836 miles.
Nautical twilight 54° 33’ 55.941” N 23,286.147101212778 km or 14,469.340986894522 miles.
Astronomical twilight 48° 33’ 55.941” N 26,570.194478309322 km or 16,509.953420964891miles.
2016 Southern Hemisphere, summer solstice: Circumference or length:
Antarctic / Arctic Circle 66° 33’ 55.524” S / N 15,983.000884214218 km or 9,931.376314954552 miles.
Civil twilight 60° 33’ 55.524” S 19,744.233388049778 km or 12,268.497840144666 miles.
Nautical twilight 54° 33’ 55.524” S 23,286.213111060426 km or 14,469.382003512255 miles.
Astronomical twilight 48° 33’ 55.524” S 26,570.255154469880 km or 16,509.991123383118 miles.
2017 Northern Hemisphere, summer solstice: Circumference or length:
Arctic / Antarctic Circle 66° 33’ 55.078” N / S 15,983.081 km or 9,931.426 international miles.
Civil twilight 60° 33’ 55.078” N 19,744.309 km or 12,268.545 international miles.
Nautical twilight 54° 33’ 55.078” N 23,286.284 km or 14,469.426 international miles.
Astronomical twilight 48° 33’ 55.078” N 26,570.320 km or 16,510.031 international miles.
2017 Southern Hemisphere, summer solstice: Circumference or length:
Antarctic / Arctic Circle 66° 33’ 54.374” S / N 15,983.206 km or 9,931.504 international miles.
Civil twilight 60° 33’ 54.374” S 19,744.428 km or 12,268.619 international miles.
Nautical twilight 54° 33’ 54.374” S 23,286.395 km or 14,469.495 international miles.
Astronomical twilight 48° 33’ 54.374” S 26,570.422 km or 16,510.095 international miles.
2018 Northern Hemisphere, summer solstice: Circumference or length:
Arctic / Antarctic Circle 66° 33’ 53.296” N / S 15,983.399 km or 9,931.624 international miles.
Civil Twilight 60° 33’ 53.296” N / S 19,744.611 km or 12,268.732 international miles.
Nautical Twilight 54° 33’ 53.296” N / S 23,286.566 km or 14,469.601 international miles.
Astronomical Twilight 48° 33’ 53.296” N / S 26,570.579 km or 16,510.192 international miles.
2018 Southern Hemisphere, summer solstice: Circumference or length:
Antarctic / Arctic Circle 66° 33’ 52.385” S / N 15,983.561 km or 9,931.724 international miles.
Civil twilight 60° 33’ 52.385” S 19,744.765 km or 12,268.828 international miles.
Nautical twilight 54° 33’ 52.385” S 23,286.710 km or 14,469.691 international miles.
Astronomical twilight 48° 33’ 52.385” S 26,570.712 km or 16,510.275 international miles.
2019 Northern Hemisphere, summer solstice: Circumference or length:
Arctic / Antarctic Circle 66° 33’ 51.083” N / S 15,983.794 km or 9,931.869 international miles.
Civil twilight 60° 33’ 51.083” N 19,744.986 km or 12,268.965 international miles.
Nautical twilight 54° 33’ 51.083” N 23,286.916 km or 14,469.819 international miles.
Astronomical twilight 48° 33’ 51.083” N 26,570.901 km or 16,510.392 international miles.
Area, calculated in the WGS84 ellipsoid:
Arctic / Antarctic 21,204,911.158404 km² or 8,187,261.969961 miles².
Civil Twilight and above i.e. 60° 33’ 51.083” N to 66° 33’ 51.083” N 11,958,971.290329 km² or 4,617,384.629143 miles².
Nautical Twilight and above i.e. 54° 33’ 51.083” N to 60° 33’ 51.083” N 14,390,453.065933 km² or 5,556,184.991160 miles².
Astronomical Twilight and above i.e. 48° 33’ 51.083” N to 54° 33’ 51.083” N 16,656,552.760405 km² or 6,431,130.974669 miles².
2019 Southern Hemisphere, summer solstice: Circumference or length:
Antarctic / Arctic Circle 66° 33’ 49.748” S / N 15,984.032 km or 9,932.017 international miles.
Civil twilight 60° 33’ 49.748” S 19,745,212 km or 12,269.106 international miles.
Nautical twilight 54° 33’ 49.748” S 23,287.127 km or 14,469.950 international miles.
Astronomical twilight 48° 33’ 49.748” S 26,571.096 km or 16,510.514 international miles.
2020 Northern Hemisphere, summer solstice: Circumference or length:
Arctic / Antarctic Circle 66° 33’ 48.571” N / S 15,984.243 km or 9,932.148 international miles.
Civil twilight 60° 33’ 48.571” N 19,745.411 km or 12,269.230 international miles.
Nautical twilight 54° 33’ 48.571” N 23,287.314 km or 14,470.066 international miles.
Astronomical twilight 48° 33’ 48.571” N 26,571.267 km or 16,510.620 international miles.
Area, calculated in the WGS84 ellipsoid:
Above Arctic / Antarctic Circle 21,206,154.924556 square km or 8,187,742.190757 square miles.
Civil Twilight and above to Arctic Circle, i.e. 60° 33’ 51.083” N to 66° 33’ 51.083” N 11,959,262.667275 square km or or 4,617,497.130411 square miles.
Nautical Twilight and above to lowest latitude for Civil Twilight, i.e. 54° 33’ 51.083” N to 60° 33’ 51.083” 14,390,726.713755 square km or 5,556,290.647175 square miles.
Astronomical Twilight and above to lowest latitude for Nautical Twilight, i.e. 48° 33’ 51.083” N to 54° 33’ 51.083” N 16,656,805.720382 square km or 6,431,228.643062 square miles.
2020 Southern Hemisphere, summer solstice: Circumference or length:
Antarctic / Arctic Circle 66° 33’ 47.077” S / N 15,984.509 km or 9,932.313 international miles.
Civil twilight 60° 33’ 47.077” S 19,745.664 km or 12,269.387 international miles.
Nautical twilight 54° 33’ 47.077” S 23,287.550 km or 14,470.213 international miles.
Astronomical twilight 48° 33’ 47.077” S 26,571.484 km or 16,510.755 international miles.
Distances personally calculated in the WGS84 ellipsoid, using Charles Karney's Online rhumb line calculations using the RhumbSolve utility: "RhumbSolve is accurate to about 15 nanometers (for the WGS84 ellipsoid)" or 0.000015 of a millimetre/millimeter or 0.00000059 of an inch. In emails to me from Charles Karney: "The accuracy of 15 nanometers that I quote is for paths up to half-way round the earth." "The accuracy for the Airy" [1830] "ellipsoid will be (very nearly) the same as for the WGS84 ellipsoid because the parameters are roughly the same." On RhumbSolve online: "RhumbSolve performs rhumb line calculations". "The path with a constant heading between two points on the ellipsoid at (lat1, lon1) and (lat2, lon2) is called the rhumb line (or loxodrome)". "NOTE: the rhumb line is not the shortest path between two points; that is the geodesic and it is calculated by GeodSolve."
Areas personally calculated in the WGS84 ellipsoid, using Charles Karney's geodesic polygon calculations using the Planimeter utility. "The result for the area is accurate to about 0.1 m² per vertex."
See also: http://www.gandraxa.com/length_of_day.xml
