Nutation
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Cause: That the celestial poles are approaching or moving away from the axis of the ecliptic, and to alter briefly retrogradation of the equinoxes and the movement of the celestial landscape.
Precession:
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Definition: This is a movement of the Earth and is produced by the gravitational effects of Sun and Moon on Ecuado
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The precession of the equinoxes is the movement that originates in the earth and travel which is the axis of rotation of the Earth Stiene an inclination of 23 ° 27 'on the wing perpendicular to the plane of its orbit, llamdo ecliptic, the inclination Earth's axis causes the tropics and polar circles.
Equinox: time of year when the days are equal to the nights, it happens two times a year, 21 March and 23 September. that the two poles of the earth are equal distance from the sun, falling as sunlight in the hemispheres N and S.
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