Equinox: Quick Facts

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Oct. 16, 2026

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Diagram showing Earth's elliptical orbit around the Sun with labeled points for aphelion, perihelion, solstices, and equinoxes, and distances from the Sun at aphelion and perihelion.

A diagram of the celestial sphere with Earth at the center, showing the celestial equator, ecliptic, and labeled positions of the vernal and autumnal equinoxes, as well as the north celestial and ecliptic poles.

sunlight strikes parts of Earth differently

Diagram showing Earth's orbit around the Sun with labeled positions for the summer solstice, winter solstice, vernal equinox, and autumnal equinox, illustrating how Earth's tilt causes the seasons.

A large tree with leaves turning orange in fall.

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View of the Andromeda Galaxy (Messier 31, M31).

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Nicolaus Copernicus. Nicolas Copernicus (1473-1543) Polish astronomer. In 1543 he published, forward proof of a Heliocentric (sun centered) universe. Coloured stipple engraving published London 1802. De revolutionibus orbium coelestium libri vi.

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