elongation

e·lon·ga·tion  (-lônggshn, -lng-, lông-, lng-)

n.

1. The act of elongating or the condition of being elongated.

2. Something that elongates; an extension.

3. The angular distance between two celestial bodies as seen from Earth.

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elongation  (-lônggshn)

The angular distance between two celestial bodies as seen from a third. Elongation is normally conceived as a measure of the angle formed between the Sun and a celestial body, such as a planet or the Moon, with Earth at the vertex. In terms of the celestial sphere, elongation is the distance between the Sun and the body as measured in degrees of celestial longitude. When the body lies on a direct line drawn from Earth to or through the Sun, its elongation is 0° and it is said to be in conjunction. It is said to be in quadrature when it lies at a right angle to a line between the Earth and Sun with an elongation of 90°, and it is in opposition when it lies on the opposite side of Earth from the Sun with an elongation of 180°. Superior planets (those that are farther from the Sun than Earth) have a full range of elongations between 0° and 180°. Inferior planets (those closer to the Sun than Earth) have limited elongations due to their smaller orbits; Venus has a greatest elongation of about 48°, while Mercury's greatest elongation is about 28°. See more at conjunctionopposition

Thesaurus

Noun	1.	elongation - the quality of being elongated longness - the property of being of long spatial extent; "one gene causes shortness and the other causes longness"
	2.	elongation - an addition to the length of something extension add-on, addition, improver - a component that is added to something to improve it; "the addition of a bathroom was a major improvement"; "the addition of cinnamon improved the flavor"
	3.	elongation - the act of lengthening something change of shape - an action that changes the shape of something