Circle of a sphere the Equator the only great circle. By contrast, all meridians of longitude, paired with their opposite meridian in the other hemisphere, form great circles. The diameter of the sphere which passes through the center of the circle is called its axis and the endpoints of this diameter are called its poles. A circle of a sphere can also be defined as the set of points at a given angular distance from a given pole. When the intersection of a sphere and a plane is not empty or a single point, it is a circle. This can be seen as follows:
Celestial Sphere Woodrow Wilson Memorial Celestial Sphere Woodrow Wilson Memorial The grounds of the Palais des Nations (seat of the United Nations Office at Geneva) contain many fine objects donated by member states of the United Nations, private sponsors and artists. The Celestial Sphere (also known as the Armillary Sphere) in the Ariana Park of the Palais des Nations is the best-known of these. The huge - over four meter diameter - "Celestial Sphere" is the chef d'oeuvre of the American sculptor Paul Manship (1885–1966). It was donated in 1939 by the Woodrow Wilson Foundation to what was then the League of Nations building. Known