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Aim: How do celestial objects appear to move in the night time sky?. Do Now: - Take the top worksheet from the back. - Explain rotation and revolution as well as what they create for the Earth.
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Aim: How do celestial objects appear to move in the night time sky? • Do Now: • - Take the top worksheet from the back. • - Explain rotation and revolution as well as what they create for the Earth. • Rotation – the earth spinning on it’s axis. Day and Night, makes Foucault pendulum appear to change direction. • Revolution – the earth moving around the sun. The seasons and the Year
I. REMEMBER! • 1) Rotation causes: • objects in the sky to rise in the east and set in the west at 15O per hour. • 2) Polaris is aligned with the North pole which causes: • objects in the sky appear to move around Polaris. • the altitude of Polaris to equal the latitude of the observer.
II. Celestial Sphere • Celestial Sphere – a “dome” around the planet with celestial objects attached to it. • Zenith – directly above an observers head. • Horizon – intersection of the celestial sphere and the ground. • Celestial objects are objects that can be seen in the sky that are not in the atmosphere.
III. The Seasons • Winter: • Winter Solstice December 21st • Sun is directly over head at the Tropic Of Capricorn (23.50 S) • Shortest Day Light Hours (about 9 hours • Summer: • -Summer Solstice June 21st • - Sun is directly over head at the Tropic of Cancer (23.50 N) • - Longest Day Light Hours (about 15 hours)
Spring and Fall: • Spring Equinox (March 21st) and Fall Equinox (September 21st) • Sun directly over head at the Equator (00) • Equal number of day light and night time hours.
Horizon W S N E
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IV. Moving Shadows The length and position of a shadow depends on both the time of year and the time of day.