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abstraction > mathematical concept > number > quantity > angle > elongation > planetary elongation

planetary elongation
subject			fact

planetary elongation	has definition The geocentric angle between a planet and the Sun, measured in the plane of the planet, Earth and Sun. Planetary elongations are measured from 0° to 180°, east or west of the Sun.
	has definition The angle planet-Earth-Sun. Eastern elongations appear east of the Sun in the evening; western elongations, west of the Sun in the morning. An elongation of 0° is called conjunction; one of 180° is called opposition: and one of 90° is called quadrature.
	is a kind of elongation
elongation	has elongation
angle	has unit angle unit
number	has value

Kinds of planetary elongation :

• greatest elongation (4 facts) - The instants when the geocentric angular distances of Mercury or Venus are at a maximum from the Sun.
• planetary elongation event (18 kinds, 57 facts) - A point in the orbit of a celestial body with a specific planetary elongation such as 0°, 90° or 180°