Physics Test 2

Uranus and Neptune are different from Jupiter and Saturn in that Uranus and Neptune

have a higher percentage of ices in their interiors. Uranus and Neptune have a greater percentage of ices in their interior because of there great distance from the Sun where temperatures are extremely cold. This allows volatiles with the lowest boiling points to condense and gather about the cores of these planets.

Earth started with about as much carbon dioxide as Venus has. On Venus, the carbon dioxide is mainly in the atmosphere. Where is it on Earth?

in rocks, in ocean, and in life

A planet in the "habitable zone"

is at a distance where liquid water can exist on the surface. The habitable zone changes depending on the stars type, but is considered to be the region in which liquid water could exist on a planets surface if it were located within that zone.

You discover a giant planet around another star. It is as big as Jupiter, but much more dense. What does the density tell you?

it has less hydrogen and helium than Jupiter

The spectroscopic radial velocity method preferentially detects

large planets close to the central star Large planets close to a star tug the star by a large amount with short periods, making those planets the easiest to detect.

The transit method preferentially detects

large planets close to the central star Observing a transit means detecting a drop in the star's light, which favors a large planet that blocks a significant amount of the star's light. A planet closer to its star transits more often, and thus it is easier to observe. Although the transit method preferentially picks out the larger planets, it is also the most effective for detecting small planets.

Nuclear reactions require very high _____________ and _____________.

temperature;density Very high temperatures and densities overcome the repulsion of like charges.

Place these images that depict different states of evolution for a planetary system in chronological order.

Cloud, dots/lines, yellow and purple system, system of planets These images present an overview of how stars like the Sun form, beginning with the gravitational collapse of a molecular cloud, and ending the ignition of a star sitting at the center of a revolving system of planets.

Place the images (Mt. Everest, highest balloon jump, cirrus clouds, commercial jet, and military jet) at their proper altitude within the troposphere or stratosphere.

bottom to top - Mountain - Clouds - Commercial jet - Military jet - record hot air balloon Mt. Everest is 8,850 m high, cirrus clouds are at about 11 km, commercial jets fly at about 12 km, military jets fly at about 18 km, and the highest balloon jump was at 39 km.

Since angular momentum is conserved, an ice-skater who throws her arms out will

rotate more slowly The ice-skater would rotate more slowly. This is an expression of the conservation of angular momentum.

Hadley circulation is broken into zonal winds by

the planet's rapid rotation. The rotation of the Earth breaks global circulation into zones. Interestingly, this process is called Taylor-Couette flow and occurs in any fluid that is rapidly rotating.

Erosion is most efficient on planets with:

wind and water Wind and water on the Earth constantly and efficiently erode and move material on the surface. As a result, there are very few craters remaining on the surface of Earth, as opposed to the Moon, from collisions during the early stages of Solar System formation.

The atmosphere of Mars is often pink-orange because

winds lift dust into the atmosphere. Dust storms cause an atmosphere to take on a reddish hue, and since dust storms on Mars are quite common, the atmosphere often takes on this appearance.

Uranus's orbit did not appear to behave according to Newton's laws of motion and gravity. The most likely culprit for Uranus's misbehaving orbit was the gravitational influence of another planet. Using Newton's laws, astronomers were able to calculate exactly where they would expect this still-undiscovered planet to be. When telescopes were pointed at this position, Neptune was seen. What does this imply?

Newton's laws have been verified by yet another test, so we should use them with high confidence until and unless they are falsified by future tests. A scientific "law" has been elevated to that status because it has been backed up by a compellingly large amount of evidence.

If a star shows a redshift in its spectrum, does that mean that the star's color has turned red?

No

Which of the following layers of the Earth's interior is composed of liquid metal?

Outer Core

If you could measure the velocities of ring particles at each distance from Saturn, you would find:

Particles in the bigger, farther rings orbit at slower speeds.

Regions A and B of a terrestrial world are the same size. Region A has 20 impact craters and region B has 5. Which region is likely to be older?

Region A

Which color star would be the hottest?

Rigel (blue)

Once all the giant planets were discovered, scientists could compare their properties to learn something about them. Study this picture, and choose the following options that match your observations.

- The planets range from having very distinct feature details with a variety of colors to being completely featureless and monochrome. - Some planets differ considerably in color from one another. Each of the Jovian planets has a unique appearance, despite being formed from the same basic processes.

Jupiter and Saturn, despite being considerably farther from us than the inner terrestrial planets, are very bright in our sky. Which of the following choices are possible explanations for this?

- They are larger than the terrestrial planets. - They are more reflective (higher albedo) than most of the terrestrial planets. Jupiter and Saturn are some of the brightest objects in the night sky (even though they are rather distant from us) because their large size allows more total sunlight to be reflected toward us, and their cloud tops reflect a large percentage of sunlight.

What causes the auroras of the giant planets?

- charged particles - strong magnetic fields All of the gas giant planets have strong magnetic fields. Charged particles become trapped in these magnetic fields and bounce back and forth between the two magnetic poles. As these charged particles collide with particles in the atmosphere, they create bright auroral rings.

What should be true about Earth's internal heat?

-It would have been greater long ago when Earth was young. - It has radioactivity and tidal stress contributing to it.

Which of the following statements is FALSE?

All the planetesimals in our Solar System have become planets.

After it was discovered, astronomers predicted Uranus's orbit using Newton's laws of motion and gravity, which had worked extremely well for all of the other planets. To their surprise, they found that their observations of Uranus's motion through the sky did not match their predictions. Which of the following would be the most logical next step?

Check for other previously undiscovered factors that might alter Uranus's orbit while still allowing it to obey Newton's laws of motion and gravity.

Consider the case of a single particle within the rings that has a highly elliptical and/or highly inclined orbit, such that its orbital shape is different from the other particles in the ring. What will likely happen to that particle?

Collisions with other particles and the gravitational force of the rings will gradually nudge it into a more circular orbit within the flat plane of the rings. Over time the gravitational influence of the entire ring will pull a highly inclined particle toward the plane of the ring.

Drag and drop each label to its appropriate location on the diagram to properly identify the processes that cause Jovian storms.

Coriolis deflection Convective upwelling Zonal winds Heat from deeper inside of Jupiter wells up through the liquid and cloud layers. When it reaches the surface, the fast rotation of the planet deflects the heated material into cyclonic rotation. Combined cyclonic storms drive zonal wind patterns on the cloud tops.

Which of the following layers of the Earth's interior should be least dense?

Crust

Why does Earth have a substantial amount of oxygen in its atmosphere while the other planets do not?

Earth is the only planet with life

As a protostar collapses, its density ______ and the temperature ________________, so the luminosity _______________.

Increases, increases, increases

Which of the following layers of Earth's interior should be the hottest?

Inner Core

Uranus is visible to the naked eye, a bit brighter than the faintest naked-eye stars. However, it was not until well after the invention of the telescope in the late 18th century that Uranus was accidently discovered. How could people have missed this naked-eye planet until then?

It has a longer orbital period than Jupiter and Saturn. Uranus's long orbital period (84 years!) would make it appear to move very slowly through the stars from night to night in relation to the stars, so it was thought to be just another star.

Rank the Jovian planets from strongest to weakest band structure (most prominent to least prominent).

Jupiter, Saturn, Uranus, Neptune

This graph shows the change in the brightness of a star during an occultation by a planet. Label the points on the curve with the correct description of what is happening at each point.

Left to right - Star is fully visible - Star is beginning to be covered - Star is totally covered - Star is emerging At the beginning of the graph, the star is at full brightness, so it is not covered by the planet. As the planet moves in front of the star, the star's light dims and quickly decreases to zero brightness. When the planet moves away from the star, the brightness quickly increases again to its maximum.

Rank the giant planets by the maximum measured wind speeds, from lowest (at left) to highest (at right).

Slowest to Fastest -100 - 150 -200 - 400 0 - 400 -700 - 350 The ranking order may seem surprising, but according to our current knowledge Jupiter has the slowest maximum wind speeds. Uranus has the next greatest, despite the odd pattern of winds caused by its sideways orientation. Saturn is next with winds of over 400 m/s (1,650 km/h), and Neptune is currently the record holder with wind speeds measured at approximately 500 m/s (2,000 km/h).

The Moon and Earth are approximately the same distance from the Sun. Why does the Moon lack an atmosphere?

The Moon has weak gravity

If Saturn's rings are made of individual small particles at varying distances from the planet, and given what you know of the laws of physics as governed by gravity, how would you expect these particles to behave?

The particles closer to Saturn will orbit faster around the planet than those farther away. Newton's law of gravity applies in this situation. Not only do particles closer to the planet have a shorter distance to travel around a single orbit, but they will also be moving faster due to the stronger gravitational force closer to the planet.

Which of the following statements about the giant planets compared to terrestrial planets is correct?

They have more mass, larger radii, lower densities, and stronger magnetic fields.

Which of the giant planets has the most extreme seasons?

Uranus With an axial tilt of about 98 degrees Uranus has the most extreme seasons, where each polar region alternately experiences 42 years of continuous sunshine, followed by 42 years of total darkness.

An occultation occurs when

a planet passes between Earth and a star. This results in the star being blocked by the planet for a short period allowing us to measure certain properties of the planet.

Metallic hydrogen is not:

a metal that acts like hydrogen It is not a metal that acts like hydrogen.

The Great Red Spot on Jupiter is

a storm that has been raging for more than 300 years. The Great Red Spot was first observed by Galileo and has been raging continuously since.

If you wanted to search for faint rings around a giant planet by sending a spacecraft on a flyby, it would be best to make your observations

after the spacecraft passed the planet. A spacecraft on a planetary flyby mission can best search for the presence of faint rings around a giant planet as it looks back on the planet after it has passed by it. From this perspective, any faint rings present would be most visible because they are backlit by sunlight passing through the diffuse material. The faint rings would be especially noticeable when the Sun is directly behind the planet from the perspective of the spacecraft.

Why is Mars so cold compared to Venus if both of their atmospheres are made mostly of carbon dioxide, a greenhouse gas?

all of the above - mars is farther from the Sun - mars has lower gravity

Why is Jupiter reddish in color?

because of the composition of its atmosphere The atmospheres of Jovian planets get their color from the ices that have condensed to form clouds. Different ices absorb and reflect light differently. For example, methane crystals make the atmospheres of Uranus and Neptune more greenish-blue.

Which of the following mechanisms contribute significantly to the formation of planetary rings?

destruction of a moon by tidal forces Ring material can come from many sources, but tidal forces, along with volcanism and impact events (collisions), are the most significant. The other options could potentially contribute, but only very small amounts. Cryovolcanism on Enceladus continuously provides material to Saturn's E ring. Gravitational capture is a very improbable event requiring a delicate gravitational dance. The Solar System is so old that any initial ring systems have collapsed into moon systems. Upper atmospheres have essentially no dust. Ring systems do not contain gases.

When viewed through a telescope, Uranus and Neptune are distinctly bluish green in color. What gas is responsible for this striking appearance?

methane Methane strongly absorbs red light and scatters blue light.

The chemical compositions of Jupiter and Saturn are most similar to those of

the Sun Jupiter and Saturn are composed almost entirely of hydrogen and helium, just like the Sun.

The words weather and climate

-refer to different size scales -refer to different timescales Weather is small scale and short term, while climate describes the average state of an atmosphere.

The greenhouse effect plays a major role in the climate of a planet. Visit the Greenhouse Effect AstroTour, and use what you learn there to choose all the statements below that are correct. Note that 273 K = 0°C = 32°F.

- The more carbon dioxide there is in an atmosphere, the stronger the greenhouse effect will be. - If there were no greenhouse effect, liquid water would not exist on the surface of the Earth. - The Earth has reached thermal equilibrium, emitting the same amount of energy into space as it absorbs from the Sun. Without greenhouse gases like carbon dioxide, the entire Earth would be well below the freezing temperature of water. These gases slow the radiation of infrared light into space, warming the planet until it reaches thermal equilibrium.

The surface pressure is related to how thick the atmosphere is (thicker atmospheres have more air molecules packed into the same volume, and thus higher pressure). Given the information in this table, how would you explain the difference in greenhouse effect strength for each of the planets?

- Venus has a very strong greenhouse effect because it has a high percentage of carbon dioxide in its atmosphere and also a high surface pressure. - Mars has a weak greenhouse effect because it has very low surface pressure. The total density of greenhouse gases in the atmosphere determines the strength of the greenhouse effect.

Put the following stages of planet formation in order of occurrence.

1. An interstellar cloud collapses into a disk of gas, dust 2. Gas pushes smaller dust grains into larger grains 3. Larger dust grains grow into clumps 4. Clumps of dust collide and stick, forming planetesimals 5. Km-sized planetesimals attract other objects by gravity 6. Planets for various sizes form The process of planet formation begins with a cloud of dust and gas that collapses to form an accretion disk. Within the disk, random motions of the gas push the dust around, and some of the dust sticks together to form larger and larger grains, eventually becoming clumps. With continued collisions, 100-meter clumps of dust grow into kilometer-sized planetesimals, which have enough gravity to grow still larger by pulling in and capturing other smaller planetesimals. The process continues until planets of various sizes are formed.

A comet is approaching Earth at a known velocity. Indicate the proper sequence that describes the wavelength of light you measure as it first approaches, then passes, and finally recedes from Earth.

1. Blueshifted 2. Rest wavelength 3. Redshifted Recall that the bluer (hotter) the light, the shorter the wavelength. When an object is approaching, we say that the light from it is blueshifted, because it is compressed to shorter wavelengths. As it passes, the light is not shifted to either shorter or longer wavelengths, but it is observed to be at rest wavelength. Moving away from you, the object's light is stretched so that it is redshifted to longer wavelengths.

Place in chronological order the following steps in the formation and evolution of Earth's atmosphere:

1. Hydrogen and helium are captured from the protoplanetary disk 2. Hydrogen and helium are lost from the atmosphere 3. Volcanoes, comets, and asteroids increase the inventory of volatile matter 4. Life releases CO2 from the subsurface into the atmosphere 5. Plant life converts CO2 to oxygen 6. Oxygen enables the growth of new life-forms Hydrogen and helium were captured from the protoplanetary disk during the formation of Earth. Hydrogen and helium are lost from the weak gravitational force of Earth. Then, volcanoes, comets, and asteroids increased the amount of volatile materials. Small organisms released CO2, which in turn promoted plant growth that turned the CO2 back into oxygen. The oxygen enabled the growth of new life-forms.

Study the radial velocity graph in the upper right panel. The blue curve shows the radial velocity of the star over a full period. What is the maximum radial velocity of the star?

28.5 m/s The maximum radial velocity is 28.5 m/s. Radial velocity is a vector quantity, which means that the value could be negative or positive depending upon the direction of motion. The maximum radial velocity is the largest positive value. Note that this value is located at the "peak" of the blue line of the Radial Velocity versus Phase graph.

The following plot represents the transit of a planet in front of its star, measured by the Kepler mission. Approximately how long did this transit last?

5 hours The duration of the event is about 5 hours, 2.5 hours before and 2.5 hours after the time of the deepest brightness dip.

A bar is a measure of atmospheric pressure, where one bar is equivalent to Earth's atmospheric pressure at sea level. Venus's atmosphere has a pressure of 92 bars. Water pressure in Earth's oceans increases by one bar for every 10 m of depth. How deep would you have to go to experience pressure equal to the atmospheric surface pressure on Venus?

920m deep Since one bar is equivalent to 10 meters of depth in water, you need to multiply the number of bars of Venus's atmosphere by 10 meters per bar. The atmospheric pressure is 92 bars. 92 bars × 10 m/bar = 920 meters

The coldest clouds in the ISM are molecular clouds, so named because their temperatures are low enough and their densities high enough for atoms to join together into molecules. These clouds are capable of collapsing to form new stars, in a stellar nursery like the one in the left image. The Pleiades (right image) is an example of stars that formed recently within such a nursery. Molecular clouds range in mass from a few times the mass of our Sun (solar masses) to 10 million solar masses. Individual stars range from 0.08 to about 150 solar masses. What does all of this imply about how stars form from molecular clouds?

A single molecular cloud fragments as it collapses, forming many stars at once. The molecular clouds that make up stellar nurseries have enough mass to make many stars, and newly formed stars tend to be seen grouped together in clusters.

The level of each of the surface-shaping processes that occur on a planet throughout its history will determine how its surface appears. The terrestrial planets were formed in basically the same environment, so we can assume that the average frequency of impacts for all of the terrestrial planets has been about the same.In a hypothetical scenario where impacts are the only process that ever shape planetary surfaces, how would the surfaces of the terrestrial planets compare?

All of the planets would have roughly the same number of craters per area.

The expansion of ocean water as it heats is a much larger contributor to sea-level rise than the addition of water from melting ice. What implications does this have for global sea levels as greenhouse gases continue to accumulate and the temperature of the oceans continues to rise?

As ocean temperatures continue to rise, expansion of ocean water will lead to larger rises in sea levels than what would be expected due to the melting of ice on land alone. As ocean temperatures continue to rise, expansion of ocean water will lead to larger rises in sea levels than what would be expected due to the melting of ice on land alone.

Based on the relation shown here between rising carbon dioxide (CO2) concentrations and average global temperatures, what is a logical prediction about what would happen if CO2 levels were to continue to rise?

Average global temperatures would increase. Average global temperatures have clearly been rising overall right along with rising carbon dioxide (and methane) concentrations. Notice that it is very important to use the full range of information shown in the graph, and not just any one small section of it. A common current argument is that average temperatures have leveled off, which would seem to be true if you only used the last 10 to 15 years. But the overall trend is very clearly that as CO2 levels increase the average temperature increases as well, and there is no reason to think that this should not continue to be the case.

The figure shown depicts the protoplanetary disk. Within the disk are dust grains of various compositions, including refractory materials, highly volatile materials, and water ice.

Beyond Saturn- Highly volatile materials Throughout the disk- refractory materials Beyond inner asteroids- water ice Because of their ability to withstand high temperatures without melting or being vaporized, refractory materials are found throughout the protoplanetary disk. Water ice is a hardier volatile and as such is found as close as the outer asteroid belt. Highly volatile materials are found beyond Saturn's orbit because they can only remain in solid form at very low temperatures far from the Sun.

Label the various processes associated with tectonism.

Big surface- spreading center (middle), subduction (right), Compression (right of big surface), Spreading (bottom left), Fault (bottom right) A spreading center currently exists between the Nazca and Pacific plates. A subduction zone exists where the Nazca Plate goes beneath the South America Plate. Compression is producing the bending and folding of western South America, and faults are helping produce the mighty mountains of the Himalayas. Spreading is represented with the small image in the lower left.

How would a sea-level rise of 60-80 meters (the range of reasonable predictions) over the next few decades affect the global population? (To help you think about this, remember that a meter is about 3 feet, and one story of a building is about 10 feet.)

Coastal regions would be flooded, driving everyone inland. If the ocean levels rose 80 meters (about 250 feet) then many of the coastal regions that are populated would become completely flooded-a very frightening prospect!

View the AstroTour Continental Drift by clicking on the link, and then select true statements from those listed below.

Convection in Earth's mantle is an energy source that breaks continental plates apart and moves them around. Over millions of years, the North and South American plates separated from the European and African plates, forming the Atlantic Ocean basin The plates upon which the continents sit are still moving, and they will continue to move indefinitely.

The oxygen molecules in Earth's atmosphere

are the result of life Earth, Mars, and Venus most likely started out with similar atmospheres and experienced similar geological histories, but the development of life on Earth increased the amount of oxygen in Earth's atmosphere.

The ozone layer protects life on Earth from

ultraviolet radiation Ozone is a thin layer that protects the Earth from the Sun's harmful UV rays.

On which of the following does plate tectonics occur?

Earth Only on Earth is plate tectonics currently active. This is based on observations of various surface features still being formed today that are associated with plate tectonics, like deep ocean trenches, mountain ranges, and volcanoes.

Which of the following statements are true? Select all that apply.

Earth's magnetosphere is essential to the formation of auroras. Earth's magnetosphere shields us from the solar wind. Earth's magnetosphere extends far beyond Earth's atmosphere. The Earth's magnetosphere extends to a radius approximately ten times the radius of the Earth. It either diverts the solar wind around the Earth or "traps" some of the charged particles within the solar wind. Some of the trapped charged particles then interact with the upper atmosphere of the Earth near the North and South poles to create auroras. Earth's magnetosphere is the strongest and largest of the terrestrial planets.

Study the sizes of the gas giants shown in the image above (the distance from the Sun increases from left to right), and choose the best explanation that accounts for their differences in size.

Gas giants decrease in size with increased distance from the Sun because the Solar Nebula was less dense farther out. Although more types of materials could condense at increasing distance from the Sun (where the temperature was colder), the Solar Nebula was less dense with increasing distance, so there was less overall material to accrete into planets. As such, the more distant giants are smaller.

Which of the following are reasons that gravity is important to star and planet formation? Choose all that apply.

Gravity causes the cloud to collapse Gravity is a force between mass objects that brings those objects together, if possible. Gravity can have effects on other aspects of a system, but gravity does not always cause or create those other aspects. For example, aspects of rotational motion and the formation of the disk are more associated with the conservation of angular momentum than with gravity. Self-gravity of a dense, cool molecular cloud can cause the collapse of the cloud, but it cannot cause the formation of an atmosphere around a planetesimal.

Study this picture of a meteorite that has been sliced open to show its interior, and use your observations to determine the most likely formation scenario for a planet.

Individual particles in the nebula stick together to form larger pieces which later collide with and stick to other pieces to gradually form larger objects, which eventually grow to the size of a planet. The mottled appearance of meteorite interiors suggests that planets were formed by smaller pieces that stuck together to form larger ones.

Properly identify the features of an impact crater using this image of a Moon crater.

Inside crater- Central peak Outside crater- Crater wall Left- Ray Above wall- Secondary crater The impact that produces a crater heats and compresses the surface it hits. Ejected material is thrown from the site to form rays (pulverized material) and secondary craters. The rebound from the deformed surface sometimes forms a central peak surrounded by a crater wall.

Label different features of the greenhouse effect on Earth.

Radiation from the Sun heating the ground -> infrared radiation radiated from ground into the atmosphere -> infrared radiation re-radiated back to ground -> infrared radiation escaping into space From left to right in the image: the Sun delivers radiation that heats the ground; infrared radiation is radiated from the ground; some infrared radiation is reradiated back to the ground by greenhouse gases; and infrared radiation escapes into space in order to balance the incoming radiation from the Sun.

Properly label the relative ages of the targeted geological features on the Moon.

Larger circle- oldest Smaller circle- younger Left- Youngest The smaller crater obscures the edge of the larger crater, meaning that the smaller crater must have occurred after the larger one. And the regions on the Moon with a distinct lack of cratering are the youngest because of a relatively recent lava flow that filled in and covered up older craters.

This image shows the path of a star as it moves through its orbit. From the point of view of an observer at the telescope, determine how the light from the star will be affected by the Doppler shift, and label each point accordingly. You may assume that the center of the star's orbit is not moving with respect to the observer.

Left- blueshifted Right- redshifted Middle- no Doppler shift When an object is moving toward an observer, its light appears to have a shorter wavelength, and is therefore "blueshifted." When an object is moving away from an observer, its light appears to have a longer wavelength, and is "redshifted." If there is no radial motion (the object is not moving at all, or is moving sideways or "transversely"), then there is no Doppler shift. Measuring the degree to which the light is shifted can give us the radial velocity of the object.

Choose the statement that corresponds to the biggest factor that resulted in Mars having a thinner atmosphere than Earth and Venus.

Mars is less massive than Earth and Venus. Mars's small size doomed it to the loss of its once-thicker atmosphere and an air pressure that is too low for liquid water to exist on the surface.

A planet's temperature depends on its distance from the Sun as well as the strength of its greenhouse effect. Let's remove the effect of distance from the Sun by just considering how the temperature of a planet changes due to the presence of its atmosphere.From the numbers given in the animation, calculate the difference in temperature for each planet with and without its atmosphere, and then rank the planets in order of increasing greenhouse effect.

Mars, Earth, Venus The temperatures of each of the planets are higher than they would be if there were no greenhouse effect and only their distance from the Sun was taken into consideration.

Comparing objects in our Solar System can give us important clues toward understanding their properties that we wouldn't obtain through just studying each object independently. Comparing Earth's Moon to those of the other planets may also help us understand more about it. Examine this table and choose the statements below it that match your observations.

Only half of the inner planets have moons. The Earth's moon is unique in that it is much larger than the moons of the other inner planets. The data show that moons are not extremely common in the inner Solar System. Earth's Moon is unique because it is the largest moon with respect to the size of its planet in the entire Solar System.

Based on the images of the moons and the properties of the objects listed, which of the following statements is correct?

Phobos and Deimos have properties that suggest that they are the same type of object as c-type asteroids. Phobos and Deimos are very small and low-density objects, with odd, potato-like shapes. This is quite different from the larger size and higher density of our Moon, which is massive enough for its gravity to have forced it into a round shape.

The following chemicals either have been or are now part of terrestrial planet atmospheres. Determine whether each is found in either a planet's primary or secondary atmosphere.

Primary atmosphere: Helium, Hydrogen Secondary atmosphere: carbon dioxide, nitrogen, oxygen, water The protoplanetary disk was composed mainly of hydrogen and helium gas, with most other materials bound up as dust or ice particles. Primary atmospheres were composed of these two gases captured from the disk, while secondary atmospheres are composed of heavier chemicals that have been constructed through various geological processes.

Sort each of the five terrestrial bodies into the appropriate category based on the type of atmosphere it currently retains, if any.

Secondary Atmosphere: Venus, Mars, Earth No Atmosphere: Mercury, Earth's moon

It is unlikely that the Moon formed elsewhere and was captured by Earth's gravity, since it may be impossible for the Earth to capture an object as large as the Moon. It is also of note that the Moon contains an unusually low quantity of volatiles, which are materials like water that are easily vaporized at high enough temperatures.Based on this, and given the moon's density, which of the following formation scenarios of the Moon most closely matches our observations?

The Moon accreted from the debris of the impact of a large object with the surface of the Earth. This would explain why the density of the Moon is similar to the density of the crust of the Earth. Such an impact would knock debris from the outer layers of the Earth into space, where it would mix with debris from the impactor, form a ring orbiting around the Earth, and then eventually accrete into the Moon.

The following graph shows the concentrations of carbon dioxide (CO2) and methane (CH4) in Earth's atmosphere for the past few hundred thousand years along with global temperatures. How do the current levels of carbon dioxide and methane in the atmosphere compare with the values seen over the last 800,000 years?

The current concentrations of both are far higher than the rest of the graph. The current concentrations of both methane and carbon dioxide are far above the normal variation in levels seen over the past 800,000 years. Methane especially has more than doubled in a short amount of time. This graph also shows a clear correlation between high concentrations and high temperatures, which is why there is much concern about these higher than average concentrations!

You are looking down on Earth from the North Pole. Recall from Chapter 2 that Earth rotates counterclockwise when viewed from this vantage point. Click the boxes that say "Include Effects of Earth's Rotation" and "Play Animation."Why are there two high tides? That is, what causes the tide on the side of the Earth away from the Moon?

The difference in force between the two sides of the planet causes both to bulge out.

Observations show that, in general, larger planets and moons have had geological activity more recently than smaller bodies have. All of the planets show past signs of volcanism, tectonics, and/or erosion, but only the larger ones are still geologically active today. Why is this? One reason has to do with the planet's interior. Most of the heat inside of Earth is left over from the accretion process during Earth's formation. What would you expect to have happened as the Earth (or any other planet) cooled after its formation?

The hard crust thickened, closing off volcanic vents, and the mantle began to solidify, slowing the motion that causes volcanism and tectonics

Measurements of the magnetic fields of the giant planets indicate what about the interior?

The interiors contain flowing, electrically conductive materials. Metallic hydrogen is hydrogen that has been compressed at very high temperatures and therefore becomes ionized and acts like a metal.

In Preset Option B, what has changed about the orbit of the planet as shown in the view in the upper left panel?

The orbital shape has changed to an ellipse, and the planet now moves at varying speeds. The orbital path has changed to an ellipse, and as a result, the planet now moves with varying speeds.

Comparing objects in a related group can reveal patterns among them. These patterns in turn can help us learn more about those objects than we could by studying each individually.With this goal in mind, watch the Introduction of the AstroTour Animation on Solar System Formation. Pay attention to the animation of the planets in the Solar System and select all of the following choices that describe the patterns that you've observed. As you do so, think about the implications of how the Solar System may have formed.

The orbits of the outer planets (those most distant from the Sun) are spaced farther apart from one another than the orbits of the inner planets. The closest planets to the Sun are much smaller than the planets that are farther away. All planets orbit the Sun in the same direction. All planets orbit the Sun in a roughly flat plane. The planets of the Solar System share similarities in their orbits. Each orbits near the same flat plane and in the same direction. These patterns offer some clues as to how the Solar System must have formed in the first place. Other patterns, such as the planets' relative sizes and distribution in space, provide additional clues about planet formation.

You are looking down on Earth from the North Pole. Recall from Chapter 2 that Earth rotates counterclockwise when viewed from this vantage point.Click the boxes that say "Include Effects of Earth's Rotation" and "Include Sun's Gravity." Now, run the simulation. Stop the simulation when the Moon is at first quarter. Remove the check mark from the "Include Sun's Gravity" box.What changed about the tides when you removed the Sun?

The strength of the tidal bulges became stronger. When the Sun is removed into the first quarter orientation, the tidal bulges increase quite a bit, that is the tides become stronger.

How would you explain the difference in cratering between these two pictures?

The surface on the right has experienced more recent volcanism or erosion than the surface to the left. In the absence of any erosion or volcanism, both regions should have the same number of craters per area. However, the image on the left has a much higher density of craters than the image on the right, so something must have happened to wipe out the craters that used to exist in the image on the right.

This figure explains how molecular clouds naturally fragment, resulting in star clusters such as the Pleiades. The Sun also likely formed in a cluster, from a single molecular cloud that fragmented to form hundreds or thousands of stars at once with a full range of masses. Yet the Sun (and most other stars) is currently a single star, with no sign of the siblings it formed with. What likely happened to the other stars in the cluster the Sun was born in?

They moved away from the Sun over the past 4.5 billion years. Open clusters, which consist of hundreds to thousands of stars, are temporary because they aren't gravitationally bound.

The diagram shown indicates the location of exoplanets orbiting their star. The light green ring represents the habitable zone for that star. Determine whether each of the planets in this system is located in a region that is too hot, too cold, or just right for liquid water to potentially exist on the surface.

Too hot for liquid water: planet b, planet c, planet d, planet e Just right for liquid water: planet f Planet f is the only one of the five planets shown that exists within the star's habitable zone, where liquid water can exist on the surface and therefore where life as we know it may potentially exist. The other planets are all too close to the star, where temperatures would be too high for liquid water to exist. In our Solar System, the only planet that is in the habitable zone is Earth. Exoplanets found within this zone are more likely to have life and are therefore good targets for the search for extraterrestrial life.

Match the geological process with the image of a landscape created by that process.

Top left- Impact cratering Top right- Tectonism Bottom left- Volcanism Bottom right- Erosion An impact on the surface leaves a round crater. When tectonic plates collide, they can thrust up mountain ranges. The eruption of molten rock onto the surface is volcanic. Rock formations weathered by wind, precipitation, or flowing water were caused by erosion.

The insert at the lower right corner of the picture is an actual image of a newly forming star. The larger picture is an artist's representation. Label each part of the picture with the name that best desribes it.

Top- Bipolar jet Middle- Protostar Right- Accretion disk As a molecular cloud core collapses, it flattens into a disk to conserve angular momentum. This disk adds, or "accretes," material onto the protostar forming in the center of the cloud and is therefore called an accretion disk. Winds from the protostar blow material away in bipolar outflows. Bipolar jets are thin lines of material blown at high velocity from each pole of the protostar.

Identify the different layers of Earth's atmosphere.

Troposphere, Stratosphere, Mesosphere, Thermosphere - The lower most atmospheric layer is the troposphere. The troposphere is the layer that humans live and breathe in. - The next layer is the stratosphere. The stratosphere contains the ozone layer, which protects us from harmful UV radiation. - The mesosphere is the next highest layer of the atmosphere and is one of the coldest layers. - The final layer is the thermosphere. The thermosphere is much hotter than the other layers.

Venus is hot and Mars is cold primarily because

Venus has a much thicker atmosphere Venus's exceptionally thick atmosphere translates into a very strong greenhouse effect. An analogy is that Mars has a comforter with two down features in it, while Venus is covered with several down comforters of heavy-winter thickness.

Select all that apply. The atmospheric greenhouse effect is present on

Venus, Earth, Mars Anywhere there are greenhouse gases (i.e., asymmetric molecules), there will be a greenhouse effect.

Label the interior areas of the terrestrial planets shown.

Venus- Crust Earth- Solid inner core, liquid outer core Moon- Core Mars- Mantle The materials within terrestrial planets have been separated by density, a process known as differentiation. When rocks of different types are mixed together, they tend to stay mixed. Once this rock melts, the denser materials sink to the bottom and the less dense materials float to the top. The core consists primarily of iron, nickel, and other dense metals. The mantle is made of medium-density materials. The crust is made of lower-density materials.

Place the pictures of different times of the molecular cloud's collapse in the correct chronological order.

When a molecular cloud core gets very dense, it collapses from the inside out. Conservation of angular momentum causes the infalling material to form an accretion disk that feeds the growing protostar.

The following graph shows the concentrations of carbon dioxide (CO2) and methane (CH4) in Earth's atmosphere for the past few hundred thousand years along with global temperatures. What is the correlation between concentrations of these two chemicals and global temperature?

When concentrations are high global temperatures are high. High concentrations of carbon dioxide and methane tend to go right along with higher global temperatures, and similarly with low concentrations and lower temperatures. Can you see why there is reason for concern about the increasingly higher concentrations of these two chemicals?

Study the Earth view panel at the top of the window. Would this planet be a good candidate for a transit observation? Why or why not?

Yes. The planet passes in front of the star from the Earth's point of view The transit method is based on the exoplanet periodically blocking some of the light from the star when it passes in front of the star as it orbits. The Earth view panel for this case shows this happening.

Impacts on the terrestrial worlds

are less common than they used to be Cratering rates today are very low, but they were very high during the early days of the Solar System.

The main greenhouse gases in the atmospheres of the terrestrial planets are

carbon dioxide and water vapor The presence of relatively small amounts of carbon dioxide and water vapor in Earth's atmosphere prevent the planet from being permanently frozen. Similarly, on Venus, the extremely dense carbon dioxide atmosphere has warmed the surface temperature to far above what would be expected at that planet's distance from the Sun.

The Coriolis effect causes winds to

circulate east and west The Coriolis effect breaks up Hadley circulation into smaller circulation cells, producing east/west zonal winds. Given the right conditions, these zonal winds appear as "stripes" in the atmosphere, as they do on the planet Jupiter. The Coriolis effect is also the reason why hurricanes rotate clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere.

When dust grains first begin to grow into larger objects, this occurs because of:

collisions between dust grains Since the mutual attractive force between these dust particles is not strong enough to overcome the internal gas pressure in the molecular cloud, they depend upon random collisions and an attractive electric force to bring them together.

Geologists can find the actual age of features on a world by

comparing cratering counts on one world to those on another. radioactive dating of rocks retrieved from the world. Both radioactive dating and comparative studies of impact rates provide useful tools for measuring the age of a feature.

If crater A is inside of crater B, we know that

crater B was formed before crater A The only way for crater A to still be seen is if it were created after crater B.

A molecular cloud fragments as it collapses because

density variations from place to place grow larger as the cloud collapses. There are small random differences in density throughout any particular molecular cloud. As it collapses, surrounding material is gravitationally drawn into the densest regions, which grow with time. The cloud then fragments and forms multiple stars.

Stellar occultations are the most accurate way to measure the _________ of a Solar System object.

diameter During a stellar occultation as seen from Earth, a moving planet blocks the light from a distance star for a certain amount of time. The amount of time that the star is hidden, combined with information about how fast the planet is moving, gives the diameter of the planet.

Individual cloud layers in the giant planets have different compositions. This happens because

different volatiles freeze out at different temperatures. Because each kind of volatile condenses at a particular temperature and pressure, each forms clouds at a different altitude. For example, methane never "freezes out" to ice in the warmer atmospheres of Jupiter and Saturn, but it is abundant in the upper cloud layers of the frigid atmospheres of Uranus and Neptune.

Erosion by wind and water has occurred on which of the following? Choose all that apply.

earth, mars Earth displays erosion by wind and water both on small and large scales today and in the past. Mars currently displays erosion by wind as its thin atmosphere shapes various dunes and hills, and it also displays erosion by water in the past with various dry riverbeds, lake basins, and tributaries.

Planetary systems are probably

exceedingly common- every star has planets Planets are a likely part of star formation and so it seems reasonable to postulate that most stars have them.

Which of the following are true? An "Earth-like" planet

has physical properties similar to Earth's An Earth-like planet has roughly the same size and mass as Earth. However, the planet need not orbit a Sun-like star; rather, the planet should be within its parent stars habitable zone.

Lava flows on the Moon and Mercury created large, smooth plains. We don't see similar features on Earth because Earth

has plate tectonics that recycle the surface. The Earth's surface is constantly moving and changing so that its surface is renewed.

On which of the following is wind erosion negligible? Select all that apply.

moon, mercury There is neither running water nor wind on Mercury or the Moon. While the atmosphere of Mars is thin, wind and dust storms still erode geologic features.

Notice that when the planet moves away from the Earth, the star moves toward Earth. The sign of the radial velocity tells the direction of the motion (toward or away).At this phase in the orbit, the radial velocity of the star is __________, and the planet's radial velocity is __________ .

negative; positive Based upon the Doppler effect, as an object moves away from the Earth, its radial velocity is positive; an object's radial velocity is negative when it moves toward the Earth. Since the star is described as moving toward the Earth, its radial velocity must be negative. The exoplanet is moving away from the Earth, and thus its radial velocity is positive.

Before you start the simulation, examine the setup. You are looking down on Earth from the North Pole.Is the distance between the Moon and the Earth to scale in this image?

no The Moon is about 380,000 km from the Earth, which is about 220 times larger than the Moon's radius. So we see from this figure that the Moon's distance from the Earth is not to scale.

Before you start the simulation, examine the setup. You are looking down on Earth from the North Pole.Are the tides shown to scale?

no The lunar tides stretch the Earth by about 30 cm (one foot) per day, which is a tiny amount compared to Earth's radius of 6,400 km. So this figure is grossly exaggerated.

The ____________ of greenhouse gas molecules affects the temperature of an atmosphere.

number It is the number of greenhouse gas molecules that is most important. For example, almost all of Mars's atmosphere is comprised of a greenhouse gas (carbon dioxide), but there is so little of it that Mars cannot retain much heat.

Scientists learn about the interior structure of planets by using

observations of magnetic fields, models of Earth's interior, observations of seismic waves Scientists use the laws of physics and the properties of materials to model exoplanets and the Earth's interior. Seismic waves, which travel through the interior of a planet, and magnetic fields, which are produced specific conditions in the interior of a planet, help scientists further refine the model.

Studying climate on other planets is important to understanding climate on Earth because

other planets offer a range of extremes to which Earth can be compared. comparing climates on other planets helps scientists understand which factors are important. other planets can be used to test atmospheric models. underlying physical processes are the same on every planet. All of the answer options are correct. In science, as well as in other areas of life, the more information that is available, the more we can learn and understand. The planets and moons of the Solar System provide excellent models to compare and contrast to each other to help better understand all of them.

Based on the law of conservation of angular momentum, what would happen to a collapsing cloud of gas and dust--isolated in space with no external forces--as its size decreases?

the cloud will spin faster The law of conservation of angular momentum states that a quantity related to the size of an object (its moment of inertia) times the speed of rotation (angular speed) has to remain the same at all times as long as no outside forces act on that object. Thus, to conserve angular momentum, a collapsing cloud must spin faster. The law of conservation of angular momentum affects the cloud's ability to continue its collapse.

The direction of revolution in the plane of the Solar System was determined by

the direction of rotation of the original cloud The answer is the direction of rotation of the orginal cloud. As a molecular cloud begins to collapse, any initial rotation will increase as the collapse continues. Conservation of angular momentum perpetuates a disk shape for the cloud, which will eventually become a central star and planar distribution of planets will rotate and revolve in the same manner as the initial rotation.

The interiors of the giant planets are heated by gravitational contraction. We know this because

the giant planets radiate more energy than they receive from the Sun. The giant planets are hotter than predicted, which means they are radiating more energy than they are receiving from the Sun. As the giant planets are large and massive enough to generate this "extra" energy via thermonuclear fusion (like within the core of the Sun), this must be due to gravitational contraction producing thermal energy. This is confirmed by noting that Jupiter, for example, is shrinking by about 1 mm per year.

Zonal winds on the giant planets are stronger than those on the terrestrial planets because

the giant planets rotate faster. The Coriolis effect carries objects in the direction of a giant planet's rotation, thus rapid rotation causes rapid wind speeds.

Auroras are the result of

the interaction of particles from the Sun and Earth's atmosphere and magnetic field. Auroras occur when charged particles from the Sun, trapped in our planet's magnetic fields, rain down on our atmosphere.

Scientists know the history of Earth's magnetic field because

the magnetic field freezes into rocks, and plate tectonics spreads the rocks out. Magnetic-field lines are frozen into rocks, which we can study to discover how the Earth's magnetic fields have changed over time.

Geologists can determine the relative age of features on a planet because

the ones on top must be younger If there are small craters on top of larger ones, the larger craters must be older, thus making the smaller ones younger.

Deep in the interiors of the giant planets, water is still a liquid even though the temperatures are tens of thousands of degrees above the boiling point of water. This can happen because

the pressure inside the giant planet is so high. The state of matter (solid, liquid, gas) depends not only on the temperature but on the pressure as well. For example, at low pressures, water at room temperature can boil (an easy experiment your professor may show you if they have a vacuum bell jar) and at very high pressures, even ultra-hot materials can stay as a liquid or a solid (rather than becoming a gas).

Which of the following quantities contribute to the angular momentum of a spinning object?

the rate of spin of the object. The mass of the object & the distribution of the mass of the object The total amount of angular momentum of a system is conserved unless an external influence changes any one of these three quantities.

The terrestrial planets and the giant planets have different compositions because

the terrestrial planets are closer to the Sun In the inner Solar System, the temperatures were too hot for the larger planetesimals to attract a significant amount of the gas that was present in the solar nebula.

The difference in climate between Venus, Earth, and Mars is primarily caused by

the thickness of their atmospheres While Mars, Earth, and Venus are all at different distances from the Sun, their temperatures depend much more strongly on the strength of the greenhouse effect, which itself is dominated by the kinds and numbers of greenhouse gases that are present. The radical difference among these three planets is dominated by the amount of greenhouse gases, that is, the thickness of the atmosphere.

You are looking down on Earth from the North Pole. Recall from Chapter 2 that Earth rotates counterclockwise when viewed from this vantage point. Click the box that says "Include Effects of Earth's Rotation."What happened to the tidal bulges?

the tidal bulges rotated a little counterclockwise

For this experiment, you will need a permanent marker, a translucent plastic cup, water, ice, and a paper or plastic bowl. Fill the cup about halfway with water and then mark the water level, labeling it so you know it's the initial level. Poke a hole in the bottom of the bowl, and place the bowl on top of the cup. Add some ice cubes to the bowl. Wait for the ice to melt completely; then mark the cup again.What happens to the water level in the cup when the ice melts?

the water level increases As the ice melts and moves from the bowl into the cup, the melted water will cause the water level in the cup to rise.

In the previous experiment, the water in the cup is analogous to the ocean, and the ice in the bowl is analogous to ice on land.Given the results of your experiment, what can you predict will happen to global sea levels when the Antarctic ice sheet, which sits on land, melts?

the water level will increases Like the ice in the bowl experiment, the ocean levels will rise.

Less massive molecules tend to escape from an atmosphere more often than more massive ones because

they are moving faster If particles have the same kinetic energy (because of their similar temperature), the less massive ones are moving much faster, helping them escape the gravity of the planet.

All weather and wind on Earth are a result of convection in the

troposphere The troposphere contains about 90% of our atmosphere and is both the air we breathe and the location of weather on Earth.