Download 8th Grade Science The Solar System Chapter 12 Study Guide The

8th Grade Science
The Solar System
Chapter 12 Study Guide
I.
The Solar System
A. Ideas About the Solar System
1. heliocentric vs. geocentric models
2. Sun contributes 99% of mass of solar system
B. How the Solar System Formed
1. Scientists believe the solar system formed about 4.5 billion years ago from a
nebula cloud that condensed
2. Eight planets in order
3. Inner planets are closer to the Sun, smaller in size, thinner atmospheres, have
weaker gravitational pull, less than 10 moons, no rings, solid and rocky, greater
density, also known as the terrestrial planets
4. Outer planets are further from the sun, larger in size, thicker atmospheres,
have stronger gravitational pull, more than 10 moons, all have rings, made
mostly of gas, less dense, also known as gas giants
5. What separates the inner and outer planets?
C. Motions of the Planets
1. Who discovered the planets revolve around the Sun in an elliptical orbit?
2. The inner planets revolve faster than the outer planets
3. Gravity and inertia cause the planets to orbit the Sun
4. Two factors that affect gravitational pull
Key terms: solar system, heliocentric, geocentric
II.
The Planets
A. Inner Planets
1. General interior layers consist of crust, mantle, and core
2. Atmosphere contains a variety of gases including nitrogen, oxygen, and carbon
dioxide
3. Solid, rocky surfaces with craters, cliffs, and mountains
4. Warmer temperatures because closer to the Sun
B. Outer Planets
1. No solid surface because mostly made of gas- may have core deep within
2. Atmosphere primarily hydrogen and helium
a. small amounts of methane in Neptune and Uranus give planets blue
color
3. Colder temperatures because further from the Sun
C. Special characteristics
1. Mercury has no atmosphere
2. What planet has the hottest temperatures and why?
3. Mars has a red color due to soil containing iron oxide (rust)
4. Saturn has the lowest density
5. What planet rotates vertically and why?
8th Grade Science
The Solar System
6. Which two planets are referred to as “sisters?”
D. Dwarf Planets
1. How many dwarf planets do we know of and what are they?
2. Dwarf planets are smaller, further from the Sun, and have a weaker
gravitational pull
3. What do dwarf planets and the other eight planets have in common?
Key terms: Mercury, Venus, Earth, Mar, Jupiter, Great Red Spot, Saturn, Uranus, Neptune, Pluto
III.
Other Objects in the Solar System
A. Comets
1. Composition of a comet
2. Structure of a comet
B. Meteoroids, Meteors, Meteorites
1. Composition of a meteoroid
2. Differentiate among a meteorite, meteor, and meteoroid
C. Asteroids
1. Composition of an asteroid
Key terms: comet, meteor, meteorite, asteroid
Short answer/essay question:
1. dwarf planets
2. inner vs outer planets
3. planetary motion