great circle(redirected from Great circles)
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Related to Great circles: Orthodrome
a sphere with three great circles shown
1. A circle described by the intersection of the surface of a sphere with a plane passing through the center of the sphere.
2. A segment of such a circle representing the shortest distance between two terrestrial points.
(Mathematics) a circular section of a sphere that has a radius equal to that of the sphere. Compare small circle
1. a circle on a sphere such that the plane containing the circle passes through the center of the sphere.
2. a circle of which a segment represents the shortest distance between two points on the surface of the earth.
A circle on the surface of a sphere whose plane passes through the center of the sphere. The Earth's equator is a great circle on the sphere of the globe.
great circle- Any circle on the surface of a sphere that lies on a plane through its center, or a circle that divides into two equal parts—as the Equator.
See also related terms for sphere.
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|Noun||1.||great circle - a circular line on the surface of a sphere formed by intersecting it with a plane passing through the center|
celestial equator, equinoctial, equinoctial circle, equinoctial line - the great circle on the celestial sphere midway between the celestial poles
ecliptic - the great circle representing the apparent annual path of the sun; the plane of the Earth's orbit around the sun; makes an angle of about 23 degrees with the equator; "all of the planets rotate the sun in approximately the same ecliptic"
equator - an imaginary line around the Earth forming the great circle that is equidistant from the north and south poles; "the equator is the boundary between the northern and southern hemispheres"
celestial horizon, horizon - the great circle on the celestial sphere whose plane passes through the sensible horizon and the center of the Earth
hour circle - a great circle on the celestial sphere that passes through both celestial poles
line - a spatial location defined by a real or imaginary unidimensional extent
line of longitude, meridian - an imaginary great circle on the surface of the earth passing through the north and south poles at right angles to the equator; "all points on the same meridian have the same longitude"
vertical circle - a great circle on the celestial sphere passing through the zenith and perpendicular to the horizon