Editing Cardinal direction (section)

===In astronomy===
In [[astronomy]], the ''cardinal points'' of an [[astronomical body]] as seen in the sky are four points defined by the directions toward which the [[celestial pole]]s lie relative to the center of the disk of the object in the sky.<ref>{{Cite journal|last=Rigge|first=W. F |title=Partial eclipse of the moon, 1918, June 24|journal=Popular Astronomy|year=1918 |volume= 26|pages=373|bibcode=1918PA.....26..373R|quote=rigge1918}}</ref><ref>{{Cite web |url=http://www.petermeadows.com/html/parallactic.html |title=Solar Observing: Parallactic Angle |last1=Meadows |first1=Peter |author2=meadows |access-date=2013-11-15 |archive-url=https://web.archive.org/web/20090207002445/http://www.petermeadows.com/html/parallactic.html |archive-date=7 February 2009 |url-status=live }}</ref>
A line (a [[great circle]] on the [[celestial sphere]]) from the center of the disk to the [[North celestial pole]] will intersect the edge of the body (the "[[wikt:limb|limb]]") at the North point. The North point will then be the point on the limb that is closest to the North celestial pole. Similarly, a line from the center to the South celestial pole will define the South point by its intersection with the limb. The points at right angles to the North and South points are the East and West points. Going around the disk clockwise from the North point, one encounters in order the West point, the South point, and then the East point. This is opposite to the order on a terrestrial map because one is looking up instead of down.

Similarly, when describing the location of one astronomical object relative to another, "north" means closer to the North celestial pole, "east" means at a higher [[right ascension]], "south" means closer to the South celestial pole, and "west" means at a lower right ascension. If one is looking at two stars that are below the North Star, for example, the one that is "east" will actually be further to the left.