AST-106beginner

Axial Tilt, Seasons & Precession: Foundations

Earth's seasons are caused primarily by the 23.5-degree tilt of its rotation axis, not by large changes in Earth-Sun distance. Axial tilt controls the seasonal cycle of insolation, while precession changes the long-term relation between the seasons and Earth's orbital position.

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Axial Tilt, Seasons & Precession: Foundations

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AST-105Earth's Rotation & Orbit: Advanced Connections→

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AST-107Axial Tilt, Seasons & Precession: Structures & Vocabulary→

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Earth's seasons are caused primarily by the 23.5-degree tilt of its rotation axis, not by large changes in Earth-Sun distance.

supported

A hemisphere tilted toward the Sun receives sunlight at a steeper angle and for more hours each day, concentrating more solar energy per unit area.

supported

Seasonal changes in noon solar altitude and day length match the geometry of axial tilt.