Unit Two Study Guide
Fundamentals of Astronomy -- ASTR 120

The Solar Nebular Theory: (Chapter 8)

1. Know the different stages involved in the Solar Nebular Theory

2. Recall the basic composition of the gas cloud out of which our solar system formed.

3. Describe how the temperature varies throughout the protoplanetary disc.

4. Explain how temperature affects the composition and size of the planets.

5. Detail the differences between the Terrestrial and Jovian planets.

6. Name the four Terrestrial and four Jovian planets.

7. Define the terms protostar, protoplanet, planetesimal, and protoplanetary disc.

8. Explain the processes by which planetary accretion occurs both early in the formation process and later in the formation process.

The Earth: (Chapter 9 for interior and seismology, 10 for atmosphere

1. Draw, and describe a cross section of the Earth, indicating its four major layers.

2. Explain how scientists gather information about the deep interior of the Earth.

3. Know what initially lead to the theory of Plate Tectonics.

4. Indicate, and explain the various geologic activities that may occur at the three (3) types of tectonic plate boundaries. (Earthquakes, Volcanoes)

5. Name and describe the three basic types of plate boundaries.

6. Be able to draw a diagram of each, and describe the relative motion between the plates.

7. Know the different layers of the Earth's atmosphere, and give one unique feature of each.

8. Explain what the how the Earth's magnetosphere is defined and describe why it is shaped the way it is.

9. Describe how the Moon and the Sun cause the tides.

10. Know the various reasons why there is little visible evidence of cratering on the surface of the Earth.

The Moon: (Chapter 9)

1. Recall the internal structure of the Moon: state of matter and composition.

2. Explain why the Moon’s crust is thinner on one side.

3. Describe how the Maria are formed.

4. Compare and contrast the type of terrain, age, and composition of the Maria and the Highlands regions of the Moon.

5. Be able to determine the relative age of two lunar features from a photograph.

6. Compare the four models of how the Earth-Moon system formed.

7. Describe in detail the Large-Impact Hypothesis of the formation of the Earth-Moon system.

Mercury: (Chapter 9)

1. Know the unique features Mercury:

   • Largest temperature difference (700K-100K)

   • Surface of Mercury and the Moon bear the closest resemblance than any other two surfaces.

2. Know what missions investigated Mercury: Mariner 10 and 11.

3. No magnetic field owing to its slow rotation.

Venus: (Chapter 9 and 10)

1. Know the unique features of Venus:

   • Hottest surface temperature (738K)

   • Most like Earth in terms of size and internal structure.

   • Has retrograde rotation.

2. Venus’ extremely hot temperature is the result of the thick atmosphere of CO₂.

3. No magnetic field owing to its slow rotation.

4. Investigated first by the Pioneer missions and radar mapped by the Magnellan mission.

Earth: (Chapter 9 and 10)

Know the unique features of Earth:

• Only planet known to have life.

• Most dense planet.

• Only planet with a significant amount of liquid surface water.

Mars: (Chapter 9 and 10)

1. Know the unique features of Mars:

   • Has the largest canyon system, Valles Marinaris.

   • Has the largest volcano, Olympus Mons.

2. Be able to compare the formation of Olympus Mons and the formation of the Hawiian Islands.

3. No magnetic field owing to its not having a liquid metallic core.

4. Visited by numerous probes including the two Viking landers, the Pathfinder lander, and the Mars Global Surveyer.

Jupiter: (Chapter 11)

1. Know the unique features of Jupiter:

   • Largest planet, twice as massive as all of the other planets combined.

   • Fastest rotation. 9.8 hours at the equator.

   • Most extensive magnetic field.

2. Large magnetic field resulting from the fast rotation and the presence of an ionized liquid (metallic) hydrogen core.

3. Io, Europa, Ganymede, and Callisto are the Galilean Moons.

4. Io, Europa, and Ganymede are close enough to Jupiter to be influence by Jupiter’s tidal forces causing internal heating of these three moons.

5. Io is the most volcanic body in the solar system.

6. Europa has a significant salt-water ocean beneath its ice crust.

7. Ganymede shows evidence of recent tectonic activity and is the largest moon in the solar system.

8. Visited by Pioneers 10 and 11, Voyagers I and II, and the Galileo spacecraft.

Saturn: (Chapter 11)

1. Know the unique features of Saturn:

   • Most elaborate ring system.

   • Most oblate planet.

2. Thin rings are held in shape by Shepherd Moons on either side of the ring.

3. Titan, Saturn’s largest moon, is the only moon in the solar system with a thick atmosphere.

4. Visited by the Voyagers I and II probes and will be visited by the Cassini probe within three to four years.

Uranus: (Chapter 11)

1. Know the unique features of Uranus:

   • First planet to be discovered telescopically, by William and Carolyn Hershel.

   • Rotates on its side, axis tilted by 98 degrees.

2. Thought to have suffered a cataclymsic collision some time in its past.

3. Evidence for this collision is seen on the surfaces of some of Uranus’ moons, Miranda and Chevron.

4. Visited only by Voyager II.

Neptune: (Chapter 11)

1. Know the unique features of Neptune:

   • First planet to be discovered through mathematics by John Adams and Le Verrier and d’ Arrest.

   • Triton is the coldest volcanic body in the solar system.

2. The fast winds on Netpune are most likely due to the atmosphere of Neptune being in a state of superfluidity, a state where the atmosphere can flow without resistance.

3. Triton is so cold that nitrogen frost is seen on its surface and it has volcanoes of liquid nitrogen.

4. Visited only by Voyager II.

Pluto: (Chapter 12)

1. Know the unique features of Pluto:

   • Most elliptical orbit, eccentricity of 25%

   • Orbits at the steepest angle to the ecliptic, 17 degrees.

   • Smallest of the nine planets.

2. Pluto was discovered by a Kansan, Clyde Toumbaugh.

3. No probe has ever investigated Pluto.

Small Bodies: (Chapter 12)

1. Asteriods:

   • Know where asteriods are generally found.

   • Recall the general structure and composition of asteriods.

2. Comets:

   • Know where comets are generally found.

   • Explain why most comets that visit the inner solar system have very elliptical orbits.

   • Be able to identify and explain the formation of the ion tail and the dust tail of a comet.

3. Kuiper Belt Objects:

   • Describe where the Kuiper Belt is in relation to the other planets.

   • Give some reasons why Pluto is considered by some not to be a planet but rather a different class of objects similar to comets.

   • Detail the structure and composition of the objects in the Kuiper Belt.

4. Define the following terms: meteor, meteoroid, and meteorite.