8.7A Rotation and Revolution

Rotation is the spinning of an object around its own axis. For example, Earth rotates on its axis once every 24 hours, causing day and night.

Revolution is the movement of one object around another object in an orbit. For example, Earth revolves around the Sun once every year.

Earth's tilt of approximately 23.5 degrees causes different parts of the planet to receive varying amounts of sunlight throughout the year, leading to the four seasons.

Day and night are caused by Earth's rotation on its axis. When one side of Earth faces the Sun, it experiences day, while the opposite side experiences night.

Position 1 represents the point in Earth's orbit where the northern hemisphere experiences the beginning of autumn.

Position 3 represents the point in Earth's orbit where the northern hemisphere experiences the beginning of spring.

Position 4 represents the point in Earth's orbit where the northern hemisphere experiences the beginning of summer.

Sunlight does not affect Earth's rotation speed, but it illuminates one side of the planet, creating day, while the other side remains dark, creating night.

A spinning basketball can model Earth's rotation by showing how one side is illuminated (day) while the other side is dark (night) when a light is shone on it.

During equinoxes, the equator experiences nearly equal amounts of day and night, as the Sun is directly above the equator.