地理極點

地理極點係行星、衛星或其它較大天體嘅自轉軸同佢表面交會嘅點。例如地球上嘅北極同南極，其它天體嘅極亦稱為南極同北極，分別會喺個天體赤道兩側各90度之處。^[1]每個行星都有地理極點。^[2]

天體自轉嘅攝動意味地理極點會喺佢表面上稍為徘迴。例如，地球嘅南北極喺幾年內會郁幾米。^[3]^[4]當製圖需要精確同不變嘅座標，^{[未記出處或冇根據]}地理極點嘅平均位置作為固定嘅製圖桿，成為物體大圓經度嘅交會點。

如果，好似地球，一個天體產生磁場，就會有磁極。^[5]

參考

↑ Kotlyakov, Vladimir; Komarova, Anna (2006). Elsevier's Dictionary of Geography: in English, Russian, French, Spanish and German. p. 557. 喺22 June 2015搵到.
↑ Hooper, William (2008). Aether and Gravitation. p. 224. 喺22 June 2015搵到.
↑ Schar, Ray (2010). Wonderfully Weird World. p. 106. 喺22 June 2015搵到.
↑ Lovett, Richard A. (2013-05-14). "Climate Change Has Shifted the Locations of Earth's North and South Poles". Scientificamerican.com. 喺2015-06-26搵到.
↑ "20 Things You Didn't Know About... the North Pole". DiscoverMagazine.com. 2014-11-18. 喺2015-06-26搵到.