Editing Canopus (section)

===Role in navigation===
[[File:Constellation_Carina.jpg|thumb|right|upright|Canopus is the brightest star in the constellation of Carina (top).]]
The southeastern wall of the [[Kaaba]] in [[Mecca]] is aligned with the rising point of Canopus, and is also named ''Janūb''.<ref>{{cite book|author=George Nicholas Atiyeh|title=The Book in the Islamic World: The Written Word and Communication in the Middle East|url=https://books.google.com/books?id=t4LEfpCW_kQC|date=1 January 1995|publisher=SUNY Press|isbn=978-0-7914-2473-5}}</ref> The [[Negev Bedouin|Bedouin]] people of the [[Negev]] and [[Sinai Peninsula|Sinai]] knew Canopus as ''Suhayl'', and used it and [[Polaris]] as the two principal stars for navigation at night. Because it disappears below the horizon in those regions, it became associated with a changeable nature, as opposed to always-visible Polaris, which was circumpolar and hence 'steadfast'.<ref>{{cite journal |last=Bailey |first=Clinton |date=1974 |title=Bedouin Star-Lore in Sinai and the Negev |journal=Bulletin of the School of Oriental and African Studies, University of London |volume=37 |issue=3 |pages=580–96 |type=abstract |doi=10.1017/S0041977X00127491 |jstor=613801|s2cid=131527348 }}</ref>

The south [[celestial pole]] can be approximately located using Canopus and two different bright stars. The first, [[Achernar]], makes an [[equilateral triangle]] between the stars and the south pole. One can also locate the pole more roughly using an imaginary line between Sirius and Canopus; Canopus will be approximately at the midpoint, being {{DEC|36}} one way to Sirius and {{DEC|37}} to the pole.<ref>{{Cite book| last1 = Heifetz| first1 = Milton| last2 = Tirion| first2 = Wil| title = A Walk Through the Heavens: A Guide to Stars and Constellations and Their Legends | date = 2007| publisher = [[Cambridge University Press]]| location = Cambridge | page = 38 | isbn=978-1-139-46138-2}}</ref>

Canopus's brightness and location well off the [[ecliptic]] make it useful for space navigation. Many spacecraft carry a special camera known as a "Canopus [[star tracker|Star Tracker]]" plus a Sun sensor for [[Orientation (geometry)|attitude]] determination. [[Mariner 4]] used Canopus for [[Spin-stabilisation|second axis stabilisation]] (after locking on the Sun) in 1964, the first time a star had been used.<ref>{{cite book |last1=United States. National Aeronautics and Space Administration. Scientific and Technical Information Division |title=Astronautics and Aeronautics, 1964: Chronology on Science, Technology and Policy |date=1965 |publisher=Scientific and Technical Information Division, National Aeronautics and Space Administration |page=398 |url=https://books.google.com/books?id=ckkCAAAAIAAJ&pg=PA398}}</ref>