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Planetary Motion. BLM 13.3a, 13.1 a,b,c Page 404. Vocabulary. Rotation Revolution Counter-clockwise Equator. Earth has 2 motions:. 1. Rotation 2. Revolution. Earth’s Rotation. Rotation – the spinning of an object around it’s axis. Axis runs North to South.
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Planetary Motion BLM 13.3a, 13.1 a,b,c Page 404
Vocabulary Rotation Revolution Counter-clockwise Equator
Earth has 2 motions: 1. Rotation 2. Revolution
Earth’s Rotation Rotation – the spinning of an object around it’s axis. Axis runs North to South. One rotation of the Earth takes 24 hours toward the east This motion causes most stars (and the Sun, Moon, and planets) to appear to rise in the east and set in the west. BLM 13.3
Earth’s Revolution Revolution – the movement of one object travelling around another. It takes the Earth one year (365.25 days) to travel, or revolve, in a circle around the Sun counter-clockwise. This motion allows us to see different constellations during different seasons. Earth-Sun Revolution animation
The Equator An imaginary line that circles the middle of the Earth East to West. This is the Equator in Kenya, Africa altitude 8538 ft. 1990
Questions Why do we only see certain stars and constellations during certain seasons? The Earth’s Revolutions. Why do we have seasons? The Earth’s Revolutions. Why does the Sun rise and set and the Moon rise and set? The Earth’s Rotations. BLM 13.3a
How do these motions effect us? Day/Night – angle affects the amount of daylight. Seasons – angle affects the type of season, not closeness to the sun. Stars are only seen during certain seasons.