elongation(redirected from elongations)
Also found in: Dictionary, Thesaurus, Medical, Legal.
Related to elongations: elongation angle
elongation,in astronomy, the angular distance between two points in the sky as measured from a third point. The elongation of a planet is usually measured as the angular distance from the sun to the planet as measured from the earth. When a planet lies on the line drawn from the earth to the sun, its elongation is 0° and is said to be in conjunctionconjunction,
in astronomy, alignment of two celestial bodies as seen from the earth. Conjunction of the moon and the planets is often determined by reference to the sun.
..... Click the link for more information. . When a planet's elongation is 90°, it is in quadraturequadrature,
in astronomy, arrangement of two celestial bodies at right angles to each other as viewed from a reference point. If the reference point is the earth and the sun is one of the bodies, a planet is in quadrature when its elongation is 90°.
..... Click the link for more information. . When its elongation is 180°, it is in oppositionopposition,
in astronomy, alignment of two celestial bodies on opposite sides of the sky as viewed from earth. Opposition of the moon or planets is often determined in reference to the sun.
..... Click the link for more information. . Elongation is measured east (eastern quadrature) or west (western quadrature) from the sun. The superior planetssuperior planet,
planet whose orbit lies outside that of the earth. The superior planets are Mars, Jupiter, Saturn, Uranus, and Neptune.
..... Click the link for more information. can have elongations between 0° and 180°; the elongations of the inferior planetsinferior planet,
planet whose orbit lies inside that of the earth. There are two inferior planets, Mercury and Venus. They always seem to be close to the sun in the sky; the greatest elongation of Mercury is 28°, and that of Venus, 47°.
..... Click the link for more information. are limited by their proximity to the sun. The greatest elongation of Mercury is 28°, and of Venus, 47°.
elongation(ee-long-gay -shŏn) The angular distance between the Sun and a planet, i.e. the angle Sun–Earth–planet, measured from 0° to 180° east or west of the Sun. It is also the angular distance between a planet and one of its satellites, i.e. the angle planet–Earth–satellite, measured from 0° east or west of the planet. An elongation of 0° is called conjunction, one of 180° is opposition, and one of 90° is quadrature (see illustration). When an inferior planet follows the Sun in its daily motion, appearing east of the Sun in the evening, it is in eastern elongation. When it precedes the Sun, appearing west of the Sun in the morning, it is in western elongation. The inferior planets, which cannot come to quadrature, reach positions of greatest elongation (GE). The GE for both eastern and western elongation varies from 18° to 28° (Mercury) and from 45° to 47° (Venus).
Elongation(religion, spiritualism, and occult)
Elongation, in astrological parlance, is the maximum angular distance that Mercury and Venus travel from the Sun. Because the orbits of Mercury and Venus lie between Earth and the Sun, these two planets appear to always travel with the Sun, so that, from the position of Earth, Mercury is always within 28° of the Sun, and Venus always within 46°. Elongation also refers to the maximum apparent distance that a satellite travels from the body around which it moves (e.g., the maximum distance the Moon travels from Earth).