1. The Solar System
Chapter 29 Review

2. Main Concepts and Big Ideas
The Heliocentric Model and Geocentric Model were ways 3 Dead Greek Guys thought the planets move in the Solar System
Terrestrial and Jovian Planets are the two major types of planets in the Solar System

3. Geocentric Model Definition: Author: Aristotle
All planets and Sun revolve around the Earth - Earth is at center of Solar System
Author: Aristotle
Problem: Geocentric Model does not explain Retrograde Motion
Earth
SUN
Mars

4. Next Dead Guy: Ptolemy
Aristotle’s Geocentric Model could not explain why a planet could have both a forward and reverse motion in the sky – Retrograde Motion
Ptolemy explained Retrograde Motion through Epicycles
Earth
SUN
Mars
Epicycle

5. Epicycles & Retrograde Motion
Orbital Path
Mars
Retrograde Motion

6. Heliocentric Model Definition: Author:
All Planets revolve around Sun
Author:
Copernicus
Confirmation of Heliocentric Model by Galileo through observations made with newly invented telescope

7. The Terrestrial Planets
The terrestrial planets are the four innermost planets in the solar system, Mercury, Venus, Earth and Mars.
They are called terrestrial because they have a compact, rocky surface like the Earth's.
The planets, Venus, Earth, and Mars have significant atmospheres while Mercury has almost none.

8. The Inner Planets Mercury
Large number of craters suggest little change since formation
Thin Atmosphere
Closeness to Sun
Small Size
Venus
Very slow rotation on axis – every 243 days
Orbital period of 224
High Volcanic Activity
Very Hot!!
Close to sun & insulating atmosphere

9. The Inner Planets Mars & Earth Common Events Earth
Volcanism
Presence of Water
Atmosphere
Earth
Escape of insulating Carbon Dioxide keeps Earth from getting too hot

10. The Jovian Planets
Jupiter, Saturn, Uranus, and Neptune are known as the Jovian (Jupiter-like) planets, because they are all gigantic compared with Earth, and they have a gaseous nature like Jupiter's.
The Jovian planets are also referred to as the gas giants, although some or all of them might have small solid cores.

11. The Outer Planets Jupiter Saturn Uranus
92% of Jupiter is Hydrogen & Helium – similar composition to Sun
Saturn
Least dense in Solar System
Period: 29.5 Years
Ring System
Uranus
Horizontal Axis – only planet that rotates this way

12. The Sun n/a Mercury 5,791,000 1.9 Venus 108,200,000 .39 A.U. 3.5
Celestial Body
Distance from sun (km)
Distance From Sun
(AU)
Comparative Distance
(Feet)
The Sun
n/a
Mercury
5,791,000
 1.9
Venus
108,200,000
.39 A.U.
 3.5
The Earth
149,600,000
1 A.U.
4.5
Mars
227,940,000
1.5 A.U
 7.5
Jupiter
778,330,000
6.2 A.U.
 25.5
Saturn
1,429,400,000
9.5 A.U.
 46.5
Uranus
2,870,990,000
19.2 A.U.
 94.1
Neptune
4,504,000,000
30.1 A.U.
 147.6

13. Asteroids, Comets, and Meteoroids
Asteroids are rocky and metallic objects that orbit the Sun but are too small to be considered planets. They are known as minor planets.
Asteroids are material left over from the formation of the solar system. One theory suggests that they are the remains of a planet that was destroyed in a massive collision long ago.

14. Asteroids
Asteroids – or Minor Planets – are fragments of rock that orbit the Sun
Most asteroids exist in a region between the orbits of Mars and Jupiter – The Asteroid Belt
Classified based on composition
Asteroids are remains of planetesimals – affected by Jupiter
Two types of asteroids NOT in Asteroid Belt between Mars and Jupiter – Trojan Asteroids & Earth Grazers

15. Comets Made of dust and ice Originate in Oort Clouds
Orbit Sun in large elliptical orbits
Coma and tail – SOLAR WIND

16. Meteoroids, Meteors and Meteorites
Meteoroids are small bits of rock or metal flying through space
Visible fireballs come from meteors burning up in atmosphere
Any part that hits the Earth is called a meteorite

17. Review Questions
Directions: At the bottom of your sheet of notes, answer the following questions:
Between the orbits of what planets is the asteroid belt located?
In what direction does the tail of the comet go?
How is a meteoroid different from a meteorite?
In what way are the orbits of Trojan asteroids and Earth Grazers unlike orbits of other asteroids?