1. (8th) Chapter 14-1 Cornell Notes
Observing the Solar System

2. Chapter 14-1 Cornell Notes
Key Questions
1. What is the difference between the “geocentric” and “heliocentric” models of the solar system?
2. Draw an ellipse.

3. Chapter 14-1 Cornell Notes
Key Terms
geocentric-
heliocentric-
ellipse-
moon-
astronomical unit (AU)-

4. Chapter 14-1 Cornell Notes Heading 1
Earth at the Center
“geo” Greek word for Earth’
geocentric: Earth at the center of the solar system;
140 AD Ptolemy added to the theory.

5. Chapter 14-1 Cornell Notes Heading 2
Sun at the Center
another Greek scientist developed heliocentric model;
heliocentric: Sun at the center of the solar system;
1500s Copernicus added the order of planets and their orbit around the sun;
Galileo invented the telescope; supported the heliocentric model.

6. Chapter 14-1 Cornell Notes Heading 3
Motions of the Planets
Copernicus wrongly thought planet’s orbits were circular;
1500s Brahe made better observations on the orbits;
Kepler developed 3 laws on planet motion:
1. Orbit is an ellipse shape;
2. Moves faster when close to the sun;
3. Orbit time is related to length from the sun.

7. Chapter 14-1 Cornell Notes Heading 4
Modern View of the Solar System
new facts about the solar system;
planets different in size and looks;
all planets but Mercury and Venus have moons;
moons are natural satellites of the planets;
Today it contains the sun, planets and moons plus other smaller objects.