The Solar Systems Study Guide
Compare the current atmospheres of Earth, Venus, and Mars in terms of composition.
Earth's atmosphere is composed mostly of nitrogen and oxygen, while Venus and Mars have atmospheres that are mostly carbon dioxide.
What evidence do we have that the surface of Europa is young and active?
Europa has very few impact craters and the icy crust of Europa is highly reflective.
Which planet has the strongest magnetic field, and hence the largest magnetosphere?
Jupiter
Why are cloud layers on Saturn less distinct than those on Jupiter for a satellite equidistant from the two planets?
Saturn is colder and cloud particles condense deeper in its atmosphere.
This animation demonstrates which of the following?
The larger the impactor, the less common it is.
Although the arrival of impactors is entirely random, which of the following is true?
The process is described by natural laws.
Where did the particles in Saturn's rings come from?
They are material ejected from the moons by impacts.
Simple craters do not have which of the following attributes?
central peaks internal rings of mountains terraces
The size of a crater on a planet, moon, or asteroid depends on which of the following?
size of the impactor velocity of the impactor strength of gravity
Why is the existence of "hot Jupiters" puzzling?
"Hot Jupiters" are found near stars in very hot places where they should not have formed and show evidence of boiling away.
Consider the following table. The Galilean Satellites Name Radius (km) Density (g/cm3) Orbital Period (days) Io 1820 3.5 1.77 Europa 1560 3.0 3.55 Ganymede 2630 1.9 7.15 Callisto 2410 1.8 16.69
(a) Rank the Galilean satellites of Jupiter in order of decreasing size. Ganymede Callisto Io Europa (b) Rank the Galilean satellites of Jupiter in order of increasing density. Callisto Ganymede Europa Io (c) Rank the Galilean satellites of Jupiter in order of decreasing distance from Jupiter. Callisto Ganymede Europa Io
Consider the following table. Composition of Jupiter and Saturn (by mass) Molecule Jupiter (%) Saturn (%) H2 78 88 He 19 11 H2O 0.0001 - CH4 0.2? 0.6 NH3 0.5? 0.2
(a) Rank the substances in the above table in order of abundance in Jupiter. hydrogen helium ammonia methane water vapor (b) Rank the substances in the above table in order of abundance in Saturn. hydrogen helium methane ammonia
Upon impact, how fast were the objects that formed craters on the moon?
10 to 70 km/sec
It takes 84 years for Uranus to orbit the sun once, so how long does each season on Uranus last?
21 years
Based on what you know about comets, select all of the correct statements from the following list.
A comet only has a tail when it is near the sun. A comet is a lump of rock and ice. A comet has actually been witnessed hitting a planet. Spacecraft have flown by comets.
What is the evidence for a liquid water ocean on Europa? (Select all that apply.)
A weak magnetic field implies the existence of a liquid layer below the surface. Europa has jagged blocks of ice that seem to have rotated and collided with each other which cannot happen on a solid moon. Long straight cracks in the icy crust are likely to happen over a liquid subsurface.
Based on what you know about the moons of Saturn, select all of the correct statements from the following list.
All of Saturn's moons are a mixture of rock and ice. Smaller moons of Saturn have cracks and smooth areas that suggest past geologic activity. Titan is the only solar system moon with a substantial atmosphere. Some of Saturn's moons may have been captured asteroids or Kuiper belt objects.
List several ways that Venus, Earth, and Mars are similar. (Select all that apply.)
All three are composed mostly of rock and metal. All three are terrestrial planets. All three have atmospheres. All three have volcanic activity on their surfaces.
The fission hypothesis can't be right for which of the following reasons?
Astronomers have not been able to show why a protoplanet would break up.
Why might we expect Venus and Earth to be similar?
Both planets are about the same size, density, and have the same chemical composition.
Based on what you know about the Moon, select all of the correct statements from the following list.
Currently, the formation of new impact craters on the Moon is rare. Most were formed billions of years ago. The side of the Moon facing Earth and the side facing away have different features. The lunar surface is covered with a layer of dust. The Moon does not have enough gravitational pull to retain an atmosphere.
How did the giant planets grow to be so large?
Far from the Sun, light elements did not get enough energy from the Sun to escape the growing gravitational fields of the outer planets, and the planets simply kept accumulating material until none was left.
Based on what you know about the moons of Jupiter, select all of the correct statements from the following list.
Ganymede probably was geologically active in the past. Callisto's old, cratered surface tells us that it has never been geologically active. Some of Jupiter's smaller moons are probably captured asteroids. Volcanic activity has been observed on Io.
How can worlds like Triton and Pluto have atmospheres when a larger world such as Ganymede has none?
Gas molecules move more slowly at low temperatures.
Why do almost all impact craters have a circular shape?
High-speed projectiles vaporize explosively upon impact, sending out spherical compression waves.
Explain the energy source that powers the volcanoes of Io.
Io's proximity to Jupiter is such that it experiences tidal heating which is enough to power volcanoes.
As the rotation of Uranus carries the planet's magnetic field around, which of the following is true of the solar wind?
It can produce enhanced aurora and magnetic storms. It can sometimes flow down into one of the magnetic poles. It can drag the magnetic field out into a corkscrew pattern.
Planetary scientists say a body has differentiated if which of the following is true?
It is separated into different layers according to density.
(a) How do you think the age of another planetary system would compare to the age of our solar system?
It should be similar. It should be older. It should be younger.
List at least three major differences between Pluto and the terrestrial planets.
Its orbit is highly elliptical and inclined to the plane of the ecliptic. It is composed mostly of ice and rock. Pluto is much smaller than the terrestrial planets.
This diagram illustrates a model of Saturn's interior. Why is the metallic hydrogen zone for Saturn smaller than Jupiter's metallic hydrogen zone?
Jupiter has more mass and thus greater gravitational compression at a depth.
Uranus has clouds of methane ice crystals. Which of the following explains why Jupiter does not have them?
Jupiter is too warm.
Why is this interesting to scientists searching for extraterrestrial life?
Life, as we know it, needs liquid water and life can be found in most places on Earth where liquid water is present.
Based on what you know about Mercury, select all of the correct statements from the following list.
Like the Moon, Mercury has many impact craters. Mercury contains a large proportion of dense metals. Mercury has a weak magnetic field.
Based on what you know about asteroid and comet impacts on Earth, select all of the correct statements from the following list.
Major impacts can trigger extinctions. Major impacts can cause global forest fires. Dust from a large impact could block sunlight for years.
The layered rock and spherical concretions seen here are evidence that water once flowed on the surface of which of the following?
Mars
Measurements from orbiting spacecraft suggests that Mars had a magnetic field in its past. How could Mars lose its magnetic field?
Mars has cooled to the point that it no longer has a fluid interior.
Based on what you learned about Mars and its moons, select all of the correct statements from the following list.
Mars has polar ice caps. Mars' moons are most likely captured. Mars seems to have been much more Earth-like in the past. Mars is smaller than Earth and Venus, but bigger than Earth's moon.
How does it compare to the composition of Earth? Of Mercury? (Select all that apply.)
Mercury has a large metal core, while the Moon does not. Earth has a large metal core, while the Moon does not. Earth contains a substantial amount of liquid, while the Moon does not.
What is the main consequence of Mercury's orbit being so highly eccentric?
Mercury's distance from the Sun varies hugely.
What is the relationship between Mercury's rotational period and orbital period?
Mercury's rotational period is two thirds of its orbital period.
Based on what you know about asteroids, select all of the correct statements from the following list.
Most asteroids have been broken by impacts. Kirkwood's gaps are caused by Jupiter. Most asteroids show no evidence of geological activity. There are some asteroids found in Jupiter's orbit.
Venus and Earth are nearly the same size and distance from the Sun. What are the main differences in the geology of the two planets? (Select all that apply.)
Only Earth appears to experience plate tectonics. Earth experiences significantly more erosion than Venus.
List several ways that they are different. (Select all that apply.)
Only Earth has liquid water on its surface. All three undergo large-scale surface changes through the different mechanisms.
What is the reason for the answer to the previous question?
Our solar system is about halfway through its evolution, and our sun is probably a second- or third-generation star.
Why haven't we detected low-mass planets close to their stars and high-mass planets far from their stars?
Our techniques are not yet sensitive enough and we have not been observing for a long enough time.
How can you can be sure the meteorite that formed the meteor crater near Flagstaff was composed of iron?
Pieces of iron were found all over the area.
In which way does Saturn differ from Jupiter?
Saturn has a smaller zone of liquid metallic hydrogen.
Based on what you know about Saturn, select all of the correct statements from the following list.
Saturn's rings are made mostly of ice particles. Smaller moons "shepherd" particles in the ring system, or keep them in their rings. Being twice as far from the Sun, Saturn is much colder than Jupiter, making its atmosphere much less active. Some ring particles are small moons that were pulled apart by tidal forces. Although it has the most extensive one, Saturn is not the only planet with a ring system.
Based on what you know about the moons of Saturn, select all of the correct statements from the following list.
Smaller moons of Saturn have cracks and smooth areas that suggest past geologic activity. Titan is the only solar system moon with a substantial atmosphere. Some of Saturn's moons may have been captured asteroids or Kuiper belt objects. All of Saturn's moons are a mixture of rock and ice.
How did the moon achieve its synchronous rotation?
The Earth raises tidal bulges on the moon. As the moon rotated through these bulges, internal friction slowed the moon's rotation until it achieved tidal coupling.
What is the composition of the Moon?
The Moon is mostly composed of silicate rock.
What evidence do we have that Mars had much more liquid water at its surface in the past than it has today?
The deuterium-hydrogen ratio is 5.5 times as high as on Earth. Martian meteorites must have formed from lava that was up to 1.8% water. We see large, dry outflow channels and valley networks on the surface of Mars. The deuterium-hydrogen ratio is 5.5 times as high as on Earth and Martian meteorites must have formed from lava that was up to 1.8% water.
Which of the following is due to the moon's small size?
The moon has no atmosphere. The moon does not have a dipole magnetic field. The moon does not have plate tectonics. The moon's surface geology is dominated by impact craters.
Why does the same side of the moon always face Earth?
The moon rotates in the same direction that it revolves and the moon's period of rotation is equal to its orbital period.
The capture hypothesis can't be right for which of the following reasons?
The moon was not torn apart by tides.
What are the moons of the outer planets made of, and how is their composition different from that of our Moon?
The moons of the outer planets consist of a mixture of ice and rock, whereas our Moon is just rock.
Why do you think the outer planets have such extensive systems of rings and moons, while the inner planets do not? (Select all that apply.)
The outer planets are larger and more massive. The temperature is much cooler in the outer solar system which allows ice particles to form and rings are partly composed of these. The outer plants have more space between them which allows them to accrete more material from the solar nebula to create rings.
Based on what you know about outer planets, select all of the correct statements from the following list.
The outer planets are larger than Earth. All Jovian planets have rings and moon systems. Pluto's characteristics do not fit in with the characteristics of the outer planets. Being rich in hydrogen, the large outer planets are low in density.
According to the large-impact hypothesis, why does the moon have a low density?
The two objects had differentiated before the impact.
Would you expect to find more impact craters on Io or Callisto? Why?
There are many more impact craters on Callisto because the impact craters on Io are removed (perhaps covered over) relatively rapidly by surface deposits from volcanic activity.
What energy source drives the weather that we see on Jupiter?
Thermal energy escaping from Jupiter's interior that is still hot from formation.
Why are Europa, Ganymede, and Callisto necessary for the continued heating of Io?
These moons periodically tug on Io and keep its orbit elliptical.
Which of the following describes planetesimals whose interiors are melted by the rapid decay of aluminum-26?
They are large enough to trap the heat in their interiors.
Which of the following is true of crater basins?
They are the largest craters on the moon. They are often deeply flooded by lava flows. They are formed by the largest impactors.
Which of the following is true of objects located in the asteroid belt?
They are the last remains of fragmented planetesimals.
What are the general characteristics of the extrasolar planets discovered so far?
They have high mass and orbit close to their stars.
Which of the following describes impactors that produce nearly all shooting stars?
They have masses less than that of a paper clip. They are composed of rock and metal. They never reach the ground.
If the moon and Earth accreted together, which of the following should be true?
They should have similar compositions.
How can Titan have a nitrogen-methane atmosphere with a surface pressure 1.5 times that of Earth's atmosphere, whereas the larger and more massive Ganymede has no atmosphere at all?
Titan is farther from the sun and thus colder than Ganymede.
Why is the surface temperature on Venus very high?
Venus has a strong greenhouse effect.
Compare the current atmospheres of Earth, Venus, and Mars in terms of the greenhouse effect.
Venus has an ongoing runaway greenhouse effect, while Mars has a runaway refrigerator effect. The Earth is currently seeing an increase in the greenhouse effect.
Compare the current atmospheres of Earth, Venus, and Mars in terms of thickness (and pressure at the surface).
Venus has the thickest atmosphere, while Mars has the thinnest.
Based on what you learned about Venus, select all of the correct statements from the following list.
Venus' atmosphere is much thicker than Earth's, and much hotter. In size and mass, Venus is very similar to Earth. Due to being closer to the sun and therefore slightly hotter than Earth when it first formed, Venus' water vapor could not condense to form oceans. This lack of carbon dioxide-absorbing liquid water has caused Venus to sufferer a runaway greenhouse effect.
How do we know that extrasolar planets are orbiting other stars?
We see a star's light dim as a planet passes in front of the star and detect alternating Doppler shifts in the spectra of some stars.
According to the graph, what is the temperature of the coldest part of Earth's atmosphere?
about 100 K
A really large impact on Earth could trigger mass extinctions as a result of which of the following?
acid rain killing plant life released greenhouse gases warming the climate dust in the atmosphere blocking sunlight
The stony-iron meteorites appear to be fragments from which of the following locations?
boundary layers between the mantles and cores of asteroids
How do we find the relative ages of the moon's maria and highlands?
by counting the number of impact craters
Which gas is most abundant in the atmospheres of Venus and Mars?
carbon dioxide (CO2)
Why are planetary magnetic fields able to change and magnetic poles able to move?
changes in the circulation of the electrically conducting interior
Planetary magnetic fields are produced by which of the following?
circulations of electrically conducting planetary interiors
Rank the stages of the moon's history in the order in which they occurred: cooling, cratering, differentiation, lava flooding, slow surface evolution.
differentiation cooling cratering lava flooding slow surface evolution
Describe the different processes that lead to substantial internal heat sources for Jupiter and Saturn. (Select all that apply.)
gravitational energy from differentiating elements primordial heat left over from the formation of the planets gravitational contraction
The meteorite that formed the meteor crater near Flagstaff, Arizona, was about as large as which of the following?
half a football field
Complex craters lack which of the following attributes?
internal rings of mountains
What are the principal features of the Moon observable with the unaided eye? (Select all that apply.)
lighter highlands dark maria
The two requirements for a strong planetary magnetic field are rapid rotation and a convective interior zone composed of an electrically conductive material. Jupiter's rotational period is slightly less than 10 hours. What type of matter present within Jupiter fulfills the second requirement?
liquid metallic hydrogen
Why do astronomers suspect that a supernova explosion occurred near the nebula that gave birth to the solar system?
meteorites contain magnesium-26
Where are the objects in the Oort cloud thought to have been formed initially?
near the present orbits of Uranus and Neptune
What is its source?
rapidly spinning liquid-metallic hydrogen just above the core
Craters are formed by which of the following?
shock waves
How are Triton and Pluto similar? (Select all that apply.)
similar in size, density and composition in the outer Solar System irregular or unusual orbits thin atmospheres of nitrogen cold worlds
The compositions of different kinds of meteorites are determined by which of the following?
the composition of different regions of fragmented asteroids
The surface age of Triton is thought to be about 100 million years. What is the evidence for such an age determination?
the density of impact craters
The temperature profile in a planet's atmosphere can depend upon which of the following?
the greenhouse effect the atmosphere's chemical composition the planet's distance from the sun
The capture hypothesis was proposed to explain which of the following?
the moon's lack of volatile elements the moon's low density the moon's lack of iron
Describe the interior heat source of Saturn.
the sinking of helium into the center releases gravitational energy heating the interior
A planet that has a dipolar magnetic field also has which of the following?
two magnetic poles
In these two radar-generated maps of the surface of Venus, you can see that the geology of Venus is dominated by which of the following?
volcanism
