PLANETARIUM:
A. LOCATION OF BRIGHT STARS AND CONSTELLATIONS
- Star Maps - How to use
- Current Sky - find bright stars
- Daily motion during current night (stars move
east to west)
- Annual Motion (see different stars at different seasons.
Fall, Winter, Spring, Summer skies
How to find bright stars
- Constellations
(for each bright star)
- Activity: locate bright stars on star map
B. MOTION OF MOON
- Daily motion - east to west
- Monthly motion - to east
- Activity: locate moon on star map re stars (not horizon);
Advance 2 days, locate new position;
Advance 2 hours, same position re stars even though
moved re horizon
C. CELESTIAL COORDINATES
- Celestial Poles, Equator, Ecliptic
- Appearance of sky from different locations on Earth: N.Pole, Equator
- Coordinates of bright stars and constellations, RA and
Declination
- Season visible
-
- Pisces: 0h (S of Pegasus)
see fall, autumnal equinox
- Gemini: 6h (near Orion)
see winter solstice
- Virgo: 12 h (near Leo)
see spring, vernal, equinox
- Sagittarius: 18h (S of Vega)
see summer solstice
D. MOTIONS
- Sun -
-
- Daily
- Annual (summer, winter)
- Ecliptic
- Moon - Path
-
- How locate re stars (project)
- Planets -
-
- Daily - E to W
- Annual - re stars - generally W to E near
ecliptic
-
- venus & mercury - always near sun
- mars, jupiter, saturn -
anywhere close to ecliptic
- Move faster and slower re stars
retrograde motion - occasionally move E to W
Why?
- Activity: mars retrograde motion, plot on map
E. HELIO- & GEO-CENTRIC MODELS OF SOLAR SYSTEM
- Review Heliocentric model:
-
- Sun stationary at center
- Earth and planets orbit sun
- moon orbits earth
- Geocentric Model
-
- Earth Stationary at Center
- Sun, planets, moon, and stars orbit earth
- Culminated in Ptolemy's model
- Test: Predicted planetary positions within 5o
(~ 10 solar diam)
- Ancients knew of Heliocentric Model, Rejected
it for 2 reasons
-
- (i) Earth motion not apparent
- (ii) No stellar Paralax
paralax
- Geocentric Model Works! aurie
- Why is Heliocentric Model Superior?
-
- Draw Heliocentric model, aurie
- Draw Geocentric model, aurie
- Conclusion:
-
- (1) Heliocentric model simpler
- (2) Heliocentric model allows explanation of
cause of motion
Bob Stein's home
page,
email: steinr@pilot.msu.edu