Chapter 25 Study Guide
Geoscience CPC
Format: Test will be a combination of multiple choice, matching, short answer, interpreting diagrams, and
short essay.
How to Prepare:
 Reread or skim chapter 25 (The summary on page 822 is helpful)
 Memorize vocabulary terms
 Reread/Rewrite/Go over out-loud you notes
 Go over quizzes and study guide questions
Chapter 25.1
Terms: geocentric, heliocentric, ecliptic plane, moon, astronomical unit, Ecliptic Plane (People: Ancient
Greeks, Ptolemy, Aristarchus, Copernicus, Galileo, Kepler)
Concepts:
 How does a geocentric model of the solar system compare to a heliocentric model?
 Who proposed/supported each model and what was the reasoning for each model?
 What is the shape of planetary orbits?
 How do gravity and inertia work to keep the planets in orbit?
 What are the components of the solar system and how is the solar system organized?
 What is an astronomical unit? How many miles/kilometers is it? Which planet is 1 AU from the sun?
Chapter 25.3: Inner Solar System
Terms: terrestrial planets, asteroids, asteroid belt
Concepts:
 How are the inner planets similar?
 What are the defining characteristics of each inner planet?
o Relative size, surface features, temps., atmosphere, geological activity; moons, etc.
o How does a planet’s atmosphere influence its temperatures?
 What are asteroids and how are they formed?
Chapter 25.4: Outer Solar System
Terms: gas giants, ring, kuiper belt, Oort cloud, comets, meteor, meteoroid, meteorite
Concepts:
 How are the gas giants similar?
 Why are the gas giants really a lot of liquid?
 What is the composition of the gas giants; temps; moons etc.
 What are the defining characteristics of each of the outer planets?
 Jupiter’s Galilean Moons: Io, Ganymede, Callisto, and Europa (Characteristics of each)
 Saturn’s moon, Titan (What’s special about it)
 Why is Pluto such an “odd ball”? Pluto “Facts”
 How do comets differ from asteroids?
 Parts of a comet; Comet tails face away from the sun
 What types of objects are in the Kuiper belt?
 What is the Oort cloud and what does is contain?
Chapter 25.5: The Origin of the Solar System
Terms: solar nebula, protoplanetary disc, planetesimals, accretion
Essay Question: Describe how our solar system formed from a cloud of dust & gas. Use key vocabulary words
and diagrams.
Concepts:
 What is the nebular theory?
 What had to happen inside the nebula for our sun to form?
 Describe the process by which planets formed in the protoplanetary disk.
 What evidence supports the nebular theory?