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
Date: Hours of Daylight:
Position of SUNRISE: Position of SUNSET :
W
E
S N
Date: Hours of Daylight:
Position of SUNRISE: Position of SUNSET :
W
E
S N
Date: Hours of Daylight:
Position of SUNRISE: Position of SUNSET :
** The noon sun is highest in summer and lowest in winter.
IV. Moving ShadowsThe length and position of a shadow
depends on both the time of year and the time of day.