Astronomy Test: Origin of the Solar System
12/10/2013
1. The Solar Nebula Theory must successfully explain which of the following phenomena?
a. The counterclockwise revolution of the planets around the sun.
b. The presence of asteroids, comets, meteoroids, and other space debris in our solar system.
c. The counterclockwise rotation of most of the solar system’s planets and moons.
d. All of the above
2. An evolutionary theory utilizes what kinds of processes or phenomena to explain the origin of the
solar system?
a. Highly improbable sudden events.
b. Gradual, highly predictable processes.
c. Revelatory processes
d. None of the above
3. Why was Pierre-Simon de Laplace’s Nebular Hypothesis revolutionary?
a. He employed Newton’s laws of gravity in his explanation.
b. He used evolutionary principles.
c. It was catastrophist in nature.
d. It was the only hypothesis to rely on vortices.
4. Why was Laplace’s hypothesis rejected?
a. Because it depended on “evolutionary forces.”
b. Because it relied on a nebular disk.
c. Because it depended on a passing star colliding with our sun.
d. Because it relied on the high angular momentum of the sun
5. Why do astronomers think the solar system formed about 4.6 billion years ago?
a. Because of radioactive dating techniques used to date meteorites and other rocks.
b. Through analyses utilizing the principles of stratigraphy.
c. The laws of uniformitarianism.
d. None of the above
6. The sun’s elemental composition, in their order importance, is what?
a. Helium, hydrogen (25%), and 2% other heavier elements.
b. Hydrogen, iron (25%), and 2% helium
c. Hydrogen, helium (25%), and 2% other heavier elements
d. None of the above
7. The chemical composition of the sun, and other stars, informs us about the chemical composition of
the solar nebula that originated our solar system.
a. True
b. False
8. The condensation sequence implies that different kinds of materials will condense in unpredictable
ways.
a. True
b. False
9. The solar nebula’s condensation sequence was determined by . . .
a. Temperature
b. Distance from the sun
c. Density of materials
d. a and b
e. none of the above
10. The solar system’s ice line (or frost line) is located where in our solar system?
a. Between Neptune and Uranus
b. Between Earth and Mars
c. Between Mars and Jupiter
d. Between Jupiter and Saturn
11. The materials making up the solar nebula were sorted by what property?
a. Mass
b. Density
c. Temperature
d. Escape velocity
12. What were/are planetesimals?
a. Protoplanets
b. Small, irregular bodies of rock and ice
c. Radioactive elements that melted planets
d. Protostars
13. What are the first two processes responsible for “building” planetesimals?
a. Gravity and fusion
b. Condensation and fission
c. Accretion and fusion
d. Condensation and accretion
14. The sticking together of solid particles, via gentle collisions, is which process?
a. Condensation
b. Accretion
15. Protoplanets were formed by . . .
a. The accretion of planetesimals
b. Gentle collisions among planetesimals and smaller protoplanets
c. Electrostatic charges and sticky coatings on the protoplanets’ surfaces.
d. All of the above
e. None of the above
16. What role did gravity play in protoplanet formation?
a. Stronger gravitational forces increased protoplanet growth rates.
b. Gravity slowed protoplanet growth by ripping planetesimal fragments apart.
c. Both a and b are correct.
d. Neither a nor b are correct.
Please use the following three words to answers questions 17-19. Each word or name can only
be used once.
Asteroids,
Comets,
half-life,
Meteoroids,
Pluto
17. _______________________ are small rocky “worlds” that are the result of a failed planet between
Mars and Jupiter.
18. _______________________ are small bits of rock and metal that occasionally enter our
atmosphere.
19. The dwarf planet _______________ is part of the Kuiper Belt.
20. The time it takes for half of a radioactive substance to decay into daughter isotope atoms is referred
to as the radioactive substance’s ______________________.
21. _______________________ are small (up to 10 km in diameter), ice-rich bodies that are leftovers
from the period of planet formation.
22. Comets provide evidence that the solar nebula lacked icy material.
a. True
b. False
23. Meteoroids have given us the opportunity to age the solar system since they are “leftovers” from
the solar system’s formation.
a. True
b. False
24. Astronomers think that the asteroids between Mars and Jupiter failed to coalesce into a planet due
to Mars’ gravitational force.
a. True
b. False
25. Where is the Kuiper Belt found?
a. In interstellar space just beyond our solar system’s boundary.
b. Between the planets Uranus and Neptune.
c. Out beyond the orbit of Neptune.
d. In the Oort Cloud beyond the solar system’s heliopause.
26. What is the Solar Nebula Theory’s Jovian problem?
a. The rate of evaporation of the nebular disk wouldn’t have allowed time for Jovian planet
formation by condensation, accretion and gravitational collapse.
b. Gravitational collapse would have taken too long and could not have “swept up” enough icy
particles to create massive planets.
c. a and b are correct
d. None of the above
27. In order to solve the SNT’s Jovian problem, astronomers have proposed what process to explain
Jovian planet formation?
a. Rapid coalescence
b. Hyper-accretion
c. Direct collapse
d. Gravitational duct tape.
28. The SNT has a problem explaining the formation of Neptune and Uranus. It appears that the two
planets are too far from the sun to have been formed by accretion.
a. True
b. False
29. According to the SNT, hydrogen and helium condensed in the inner part of the nebular disk.
a. True
b. False
30. (Short essay question) What is the importance of the solar system’s ice line?
31. (Challenge question – worth 2 points) According to the SNT, why should planets be very common?
32. (Challenge question – worth 2 points) What do we utilize to study the Solar Nebula Theory?
33. (Challenge question – worth 2 points) Explain how direct collapse would work in the formation of
the Jovian planets.