GEOL 109 Final Exam
Which of the following are true about planetary accretion? (Select all that apply.)
- As these particles accreted, the planets became hot as kinetic energy was converted to thermal energy. - The planets grew larger and larger via repeated impact. - The planets became internally differentiated to different degrees. - The particles that accreted to form the planets were in orbit around the Sun. ALL
What is a major difference between planets and stars? (Select all that apply.)
- Planets are much smaller in diameter than the stars around which they revolve. - Planets do not generate energy through nuclear fusion.
What are the major differences between a moon and a planet? (Select all that apply.)
- Planets revolve around the Sun. - Moons revolve around a Sun-orbiting planet.
The most basic subatomic particles include which of the following? (Select all that apply.)
- Protons - Neutrons - Electrons
Which of the following are the characteristics of the asteroid belt? (Select all that apply.)
- The asteroids mark the transition from the rocky terrestrial planets to the outer planets. - Some asteroids appear to be rocky; some seem covered with lava; others seem to be metallic; and yet others may have water ice. - Many meteorites that fall on Earth come from the asteroid belt.
Which of the following are characteristics of the orbits of the objects that accrete to make planets? (Select all that apply.)
- Their orbits form a flattened disk shape. - They orbit in the equatorial plane (ecliptic) of the star.
Which of the following is correct about the nebulas we see in the sky today? (Select all that apply.)
- They are concentrations of interstellar gas and dust. - Many are the birth grounds of stars. - Some form when stars explode.
Which of the following are correct about red giant stars? (Select all that apply.)
- They form as a star expands and the surface cools. - They evolve from medium-sized stars.
Large planetary bodies failed to accrete in some parts of the solar system and did not sweep their neighborhoods clear of debris. Select the two most prominent zones of this "debris."
- between Mars and Jupiter - beyond Neptune
Lesson 1: The Solar System
...
Lesson 29
...
Lesson 2: Origin of the Elements
...
Lesson 32
...
Lesson 33
...
Lesson 34
...
Lesson 35
...
Lesson 36
...
Lesson 37
...
Lesson 3: Condensation
...
Lesson 4: Accretion of the Planets
...
Condensation in the solar nebula and accretion of planets is thought to have occurred about how many years ago?
4,500,000,000 y
Would you expect to find young basaltic lavas at the surface of Callisto? Why? (Select all that apply.)
A & B - No, because it is too cold. - No, because it does not have silicates near the surface that could melt.
The Roche limit _________________________. (Select all that apply.)
A & C - is produced by tidal interaction between two planetary bodies - governs the distance within which orbiting materials will not accrete together
What is evidence that many of the outer moons of Saturn are captured rather than formed in orbit around Saturn? (Choose all that apply.)
A & D - Many of them have highly inclined orbits. - Many have retrograde orbits around Saturn.
In what way is the magnetic field of Uranus distinctive? Choose all that apply.
A, B, C - It has an unexpected orientation - It is tilted compared to the spin axis - It is irregular and may be experiencing a reversal.
What are the principal differences between Titan and the other satellites of Saturn? (Select all that apply.)
A, C, E - Titan is the the biggest moon of Saturn. - Titan has liquids that flow and pond on its surface. - Titan is the only moon with dunes.
Which of the following Earth-like features have been identified on Titan? (Select all that apply.)
ALL - EXCEPT tectonics and glaciers
According to our best modern day evidence, how long ago was the Big Bang?
About 14 billion years ago.
The inner planets
All of these are incorrect.
This diagram shows the layered structure of Jupiter. Click on the zone that consists of metallic hydrogen.
B
Which letter on this image of Ariel's surface labels an area that has evidence for late expansion and possible volcanism? Click on your answer.
B
When comparing Jupiter and Saturn, which of the following is correct? (Select all that apply.)
B & D - Jupiter is denser. - Jupiter has more large satellites (those larger than the moon).
Complete this sentence. Some of the satellites of Saturn ____________________. (Select all that apply.)
B & D - orbit closer to the planet than its famous rings - have equatorial ridges formed by accumulation of ring materials
What are some important characteristics of the atmosphere of Jupiter? (Select all that apply.)
B, D, E - The clouds are made of ices of ammonia (NH3) and water. - Jupiter's atmosphere formed by trapping nebula gas on to a large icy core. - It is poor in carbon dioxide, unlike Mars.
Why was it surprising to discover that Enceladus had the features you just identified?
Because it is so small, young surfaces were not expected. It should have cooled long ago.
Why is Neptune blue?
Because its atmosphere contains a significant proportion of methane.
How did the giant outer planets obtain their thick atmospheres?
By collapse of nebular gas onto a protoplanet's icy core.
Enceladus (500 km across) and Mimas (400 km across) are both small, icy moons with about the same diameter. Enceladus is shown here. Which letter labels a feature that makes Enceladus so different from Mimas? Click on your answer.
C
Which of the letters on this image of Titan's dunes labels a feature that is the strongest evidence for the movement of sand in the dunes? Click on your answer.
C
Which of the Galilean satellites of Jupiter has the most heavily cratered surface.
Callisto
What is the most important source of energy that drives the circulation of Saturn's atmosphere?
heat released from the interior
Which list is made of very volatile materials?
helium (He), argon (Ar), ammonia (NH3), and methane (CH4)
What is the most abundant of the gases comprising Saturn?
hydrogen
Jupiter is composed mainly of ____________.
hydrogen and helium
What is the origin of the features identified in question 2?
icy volcanism and tidal heating
The T-Tauri phase of a star's history
is typified by extreme fluctuations in energy and a strong magnetic field
Titan's atmosphere is rich in nitrogen (N2) and _____________.
methane (CH4)
Water ice is
most abundant on the moons of the outer planets
What is the principal method of light element (up to iron, atomic number 26) production?
nuclear fusion
The icy layers of Jupiter's satellites increase in thickness as one moves from Europa to Callisto because ____________________. (Select all that apply.)
they accreted in a thermal gradient centered around Jupiter
Examples of highly refractory materials are
tungsten (W), osmium (Os), and zirconium (Zr)
Which kind of stars have the longest lifetimes (~10 billion years)?
Medium-sized stars like our Sun.
Where is Saturn's Roche limit for small icy bodies in orbit around it?
Near the outer edge of the rings.
What causes the Cassini Division, the 400 km wide break in the rings of Saturn?
Orbital resonance of the ring particles with the larger satellites.
Which of the following is true about Saturn's rings?
The rings are composed of many small particles of water ice in orbit around Saturn.
Why are many of Saturn's moons shaped like this one (Phoebe), instead of being essentially spherical?
The size and hence the gravity field are not large enough to deform the irregular bodies into near spherical shapes.
Why are the inner planets depleted (poor) in volatile elements?
Their constituents condensed at high temperatures.
Which statement is true for the outer planets of our solar system?
They are largely made of hydrogen and helium.
What is the evidence that the moons of Saturn are generally icy?
They have densities less than 2.0 g/cm3.
What were the most common solids that condensed from the solar nebular gases?
They were water ice.
The only satellite of Jupiter or Saturn known to have a substantial atmosphere is _________________.
Titan
Why does Titan have an atmosphere rich in nitrogen and methane while the Galilean satellites of Jupiter lack atmospheres?
Titan formed farther from the Sun where ammonia and methane ice were stable in the ancient accretion disk.
The banding of Jupiter's atmosphere is probably related to which of the following?
Turbulent winds in the atmosphere of this rapidly spinning planet.
Why does the interior of Uranus appear to lack a layer of metallic hydrogen like those in Saturn and Jupiter?
Uranus is too small and the internal temperature and pressure are not high enough for metallic hydrogen.
Which of the following objects is most like Earth in size and composition?
Venus
How will the Sun's life probably end?
With the formation of a planetary nebula.
Many supernovas are the result of
collapse of a star with multiple burning shells
Arrange these images of Jupiter's satellites by their distance from Jupiter as they orbit. Place the closest satellite on the top and the farthest one on the bottom.
colorful, blueish, starred with stripes, just stars
Which of the following is a common process that occurred during the evolution of the satellites of Uranus?
cracking as they expanded late in their histories
The particles in the rings of Uranus are ______________________.
dark and probably composed of darkened methane ice
Most of the mass of the solar nebula resided in materials which
did not condense to form solids.
Which is the correct sequence of planets, based on increasing average radius of their orbits?
Closest to Sun Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune Pluto Farthest from Sun
How are the rings of Jupiter related to the small moons Adrastea and Metis?
Collisions at the surface of these bodies may send showers of small particles spiraling inward to Jupiter.
Which objects have orbits that take them the farthest from the Sun in our solar system?
Comets
Where does Jupiter's large magnetic field come from?
Convection in a layer of ionized hydrogen may create the magnetic field.
Compared to Jupiter, Saturn has a yellowish tint. What gives it this color?
Crystals of ammonia ice in the clouds
Why isn't Earth's Moon heated by tidal flexing? (Select all that apply.)
D & E - The orbit of the Moon is nearly circular. - Earth only has one large moon, unlike Jupiter.
How are elements heavier than iron produced?
During a supernova explosion
If you were a solar system explorer in search of liquid water at or near the surface, which of the satellites of Jupiter would be most likely to have it today?
Europa
The composition of the surface of Ganymede is most like which of the other satellites of Jupiter?
Europa
Which is true about our current understanding of extrasolar planets (exoplanets)?
Exoplanets are common and found around many different types of stars.
Put the following stages in the evolution of a medium-sized star in the correct time order, placing the first stage on the top and the last stage on the bottom.
First Stage Molecular Cloud Protostar Main Sequence Star Red Giant Planetary Nebula Last Stage
Which of the following are common features on the icy satellites of Saturn?
Global rifts apparently caused by expansion.
Think about the process of planetary accretion. Which statement best describes our current ideas about the rate of impact cratering in the inner solar system?
Initially, the rate declined smoothly, but there was a later episode of heavy bombardment followed by resumption of the decline.
Why is Jupiter so much larger than all of the terrestrial planets combined?
It formed in the outer solar system where water ice was stable.
A giant molecular cloud is best described by which statement?
It is a cool mass of gas and dust that can be light years across.
Jupiter is different from the terrestrial planets in what important way?
It radiates more energy than it receives from the Sun.
Why is it appropriate to call Uranus the "oddball" planet?
Its spin axis is tipped from vertical by over 90 degrees.
Saturn is the most similar in composition and internal structure to which of the planets below.
Jupiter
What do the features in this image imply about the geologic history of Titan?
Rivers of liquid have flowed across the surface and eroded it.
Which of the following is involved in collisional accretion?
The aggregation of planetismals when they impact one another.
Which of these is evidence for planetary accretion?
The heavily cratered surfaces of the Moon and other planetary bodies.
The spin axes of some planets are tilted relative to the plane in which most orbit. What could have caused this?
The impact of a large object late in the history of accretion changed the spin.
What is the most likely explanation for Saturn's magnetic field?
The magnetic field forms by convection in a shell of metallic hydrogen.
What sets the composition of the moons of the outer planets apart from the inner planets?
The moons of the outer planets generally have lower densities.
Which of the following best describes the orbital evolution of the planets in our solar system according to the Nice Model?
The orbits of the outer planets changed significantly about 3.9 billion years ago as Uranus and Neptune moved outward from the Sun.
The last 2 or 3 billion years of the histories of the small inner planets (like the Moon and Mercury) are dominated by contraction, whereas the late histories of the small icy satellites of Saturn and Uranus are dominated by expansion like that evidenced in Ariel. Why?
The outer planet satellites have a lot of water ice that expands as it freezes.
When did the planets form?
The planets formed about the same time as the Sun in a relatively short period of time only a few million years long.
A "star" that shines, but not as a result of nuclear reactions, is called a __________.
protostar
In what way are the icy moons of Uranus different from those of Saturn?
slightly higher densities
