ast 103 - test 3 Flashcards
The lithosphere of a planet is the layer that consists of?
The rigid rocky material of the crust and uppermost portion of the mantle.
Which internal energy source produces heat by converting gravitational potential energy into thermal energy?
Accretion and differentiation
Which internal energy source is the most important in continuing to heat the terrestrial planets today?
Radioactivity
Which of the following shows evidence of ancient river beds?
Mars
How does seafloor crust differ from continental crust?
Seafloor crust is thinner, younger, and higher in density
How large is an impact crater compared to the size of the impactor?
10 times larger
The terrestrial planet cores contain mostly metal because?
Metals sank to the center during a time when the interiors were molten throughout
How fast do plates move on Earth?
A few centimeters per year
The relatively few craters that we see within the lunar maria
Were formed by impacts that occurred after those that formed most of the craters in the lunar highlands
A planet is most likely to have tectonic activity if it has
high internal temperature
Which of the following is not evidence for plate tectonics on Earth?
the existence of volcanos
Why does Venus have such a great difference in temperature between its “no atmosphere” temperature and its actual temperature?
It has a large amount of greenhouse gases in its atmosphere
Convection occurs in the troposphere but not in the stratosphere because
Lower altitudes of the troposphere are warmer than higher altitudes, unlike in the stratosphere
Why does the burning of fossil fuels increase the greenhouse effect on Earth?
Burning releases carbon dioxide into the atmosphere
Earth has been gradually warming over the past few decades. Based on a great deal of evidence, scientists believe that this warming is caused by
human activities that are increasing the concentrations of greenhouse gases in Earth’s atmosphere
How many more times is the atmospheric pressure in Jupiter’s core greater than the atmospheric pressure at Earth’s surface?
100 million
The Huygens probe took numerous pictures as it descended to Titan’s surface in 2005. What did the pictures show?
features erosion, including what appears to be dry river valleys and lakebeds
According to our theory of solar system formation, why did Uranus and Neptune end up to be much less massive than Jupiter and Saturn?
Particles in the solar nebula were more spread out at greater distances, so the accretion took longer and there was less time to pull in gas before the solar wind cleared the nebula
Which of the following best describes why we see horizontal “stripes” in photographs of Jupiter and Saturn?
The light stripes are regions of high clouds, and the dark stripes are regions where we can see down to deeper, darker clouds
How does the greenhouse effect work?
Greenhouse gases absorb thermal radiation that is emitted by the surface
How much of the mass of the moon system around Jupiter is in regular moons rather than irregular moons?
99.997%
What is a regular satellite?
one that is in a coplanar and circular orbit
What kind of surface features may result from tectonics?
All of the above
A) Mountains
B) Valleys
C) Cliffs
Which of the following best describes why the smaller terrestrial worlds have cooler interiors than the larger ones?
They have relatively more surface area compared to their volumes
What drives the motion of the tectonic plates on Earth?
convection cells in the mantles
Why are there fewer large craters on the seafloor than on the continents?
The seafloor crust is younger than the continental crust
Volcanism is more likely on a planet that
has high internal temperatures
Which of the following describes impact cratering
The excavation of bowl-shaped depressions by asteroids or comets striking a planet’s surface
There is no aurora on Venus because it lacks
lacks a strong magnetic field
Which of the following best describes rain on Venus?
It has sulfuric acid rain in its atmosphere, but the drops evaporate before hitting the surface
What is required for convection to take place?
the substance must be strongly heated from underneath
Which two geological processes appear to have been most important in shaping the present surface of Venus?
volcanoes and tectonics
What is differentiation in planetary geology?
the process by which gravity separates materials according to density
Why does the Earth have a stronger magnetic field than the other terrestrial worlds?
It is the only one that has both a partially molten metallic core and reasonably rapid rotation.
Earth’s stratosphere is heated primarily by which process?
Absorption of ultraviolet radiation by ozone.
What are greenhouse gases?
gases that absorb infrared light
What is the difference in meaning between the terms weather and climate?
Weather refers to short-term variations in conditions, and climate refers to long-term variations in conditions.
Why would the weather become more severe as the greenhouse effect increased?
Warming would increase the evaporation of the oceans, leading to more water in the atmosphere and more frequent and severe storms.
What is a magnetosphere?
a region of space around a planet in which the planets magnetic field can trap charged particles
Why is thermal escape of atmospheric gas much easier from the Moon than from Earth?
The Moon’s gravity is so much weaker than Earth’s.
The four Galilean moons around Jupiter are
a mixture of rock and ice.
What is the most important reason why an icy moon is more likely to be geologically active than a rocky moon of the same size?
Ice has a lower melting point than rock.
How thick are Saturn’s rings from top to bottom?
a few tens of meters
Why are Saturn’s rings so thin?
Any particle in the ring with an orbital tilt would collide with other ring particles, flattening its orbit
What is the most abundant gas in Titans atmosphere?
nitrogen
The energy in the atmospheres of most of the jovian planets comes
both the Sun and their interiors, in roughly equal proportions.
Overall, Jupiter’s composition is most like that of
the Sun’s
What would happen to Jupiter if we could somehow double its mass?
Its density would increase but its diameter would barely change
How does Io get heated by Jupiter?
tidal resonance
Which of the following is not a similarity between all jovian planet ring systems?
they all have features shaped by moons and resonances
Where is Neptune’s magnetic field generated?
in an ocean of hydrogen compounds, rocks, and metals
Sunsets are red beccause
sunlight must pass through more atmosphere then, and the atmosphere scatters even more light at bluer wavelengths, transmitting mostly red light
The strength of the Coriolis effect depends on
a planet’s size and rotation rate
Why does atmospheric pressure decrease with altitude?
the weight of the atmosphere above decreases as altitude increases
Which of the following increases atmospheric loss by thermal escape?
increasing the temperature of the atmosphere
Io, Europa, and Ganymede have tidal heating because
an orbital resonance keeps their orbits elliptical.
What is the liquid in Titan’s rivers and lakes?
methane and ethane
Venus may have started with an ocean’s worth of water. Where is its water now?
The water was lost when ultraviolet light broke apart water molecules and the hydrogen escaped to space
Why are methane clouds not seen on Jupiter and Saturn?
the atmospheres of Jupiter and Saturn are too warm for methane clouds to form
How do seasons on Mars differ from seasons on Earth?
they are more extreme because of Mars’s larger orbital eccentricity
What is unusual about Triton?
it has a backwards orbit
Which of the following is not a greenhouse gas?
ozone
