1. Ch. 29 The Solar System

2. 29.1 Models of the Solar System
Geocentric model: Earth centered model developed by Aristotle
Did not fit observations such as retrograde motion, the backward motion as some planets appear to reverse direction…..

3. Epicycle model: Planets revolved around earth, but then planets moved in small chain like circles
This model considered the observations and attempted to account for them!!!

4. Heliocentric Model Developed by Copernicus
Sun centered model of the Solar System
Planets orbit in the same direction
Each planet moves at a different speed and distance from the sun

5. Kepler’s Laws: Ellipses

6. Kepler’s Laws: Ellipses

7. Kepler’s Laws: Ellipses

8. Kepler’s Laws
First Law (Law of Ellipses): The orbits of planets are ellipses with the sun at one focus

9. Kepler’s Laws
Second Law (Law of Equal Area): Planetary motion will cover the same area in a given unit of time.

10. Third Law (Law of Periods):
r3 ~ p2
The distance of a planet from the sun cubed (r3) is proportional to the square of the period (p2).
Period is defined as the length of time for one revolution around the sun.

11. Kepler’s 3rd Law
Notes

12. 29.2 The Inner Planets Four Planets closest to the sun.
Terrestrial Planets : rock like planets, similar to Earth
During the formation of the solar system, materials with low boiling points where driven off.

13. Mercury Planet closest to the sun Period: 88 days Length of a day:
59 Earth Days!!!!
Minimal Atmosphere, and slow rotation = HUGE temperature changes between night and day, 427C and -173  C

14. Venus Period: 225 days Rotation: 243 days Same size, mass, and
density as Earth!
Dense Atmosphere
(96% CO2)
Average surface temperature is 464C

15. Earth Third Planet from the Sun Period: 365.24 days
Rotation: 23 hours, 56 minutes
Geological Activity
Because of the lower amounts of CO2, heat is able to escape.
Average temperature: 14C

16. Mars Fourth planet from the sun. Period: 687 days
Rotation: 24 hours, 37 minutes
2 Moons
Geologically active
Volcanoes: Olympus Mons
Water is trapped at ice caps

17. How old would you be on another planet???
In class math applications activity