Astronomy Exam 2- Practice Tests
What can we conclude when we see a region of a planet that is not as heavily cratered as other regions? a. The surface in the region is older than the surface in more heavily cratered regions. b. The planet formed after the age of bombardment and missed out on getting hit by leftover planetesimals. c. The planet is rotating very slowly and only one side was hit by impactors. d. The surface in the region is younger than the surface in more heavily cratered regions. There is little volcanic activity to create craters.
d
The jovian planets in our solar system are a. Pluto and Eris. b. Mercury, Venus, Earth, and Mars. c. Io, Europa, Ganymede, and Callisto. d. Jupiter, Saturn, Uranus, and Neptune.
d
According to our theory of solar system formation, which law best explains why the central regions of the solar nebula got hotter as the nebula shrank in size? a. the law of conservation of energy b. the two laws of thermal radiation c. the law of conservation of angular momentum d. the law of universal gravitation
a
An impact crater that is 10 kilometers across was probably made by the impact of an object about ________ across. a. 1 kilometer b. 100 meters c. 100 kilometers d. 10 kilometers e. 10 meters
a
Based on its surface features, the most important event on Venus in the past billion years or so was a. a global "repaving" that erased essentially all the surface features that had existed earlier b. the eruption of a giant volcano that formed one of Venus's "continents" c. the impact of an unusually large asteroid that left a deep scar on one side of the planet d. the onset of mantle convection, which caused Venus's lithosphere to split into plates like those on Earth
a
If we observe one edge of a planet to be redshifted and the opposite edge to be blueshifted, what can we conclude about the planet? a. The planet is rotating. b. We must actually be observing moons orbiting the planet in opposite directions, not the planet itself. c. The planet is in the process of falling apart. d. The planet is in the process of formation.
a
In what way is Venus most similar to Earth? a. Both planets are nearly the same size. b. Both planets have similar surface geology. c. Both planets have similar atmospheres. d. Both planets have warm days and cool nights.
a
Laboratory measurements show hydrogen produces a spectral line at a wavelength of 486.1 nanometers (nm). A particular star's spectrum shows the same hydrogen line at a wavelength of 486.0 nm. What can we conclude? a. The star is moving toward us. b. The star is moving away from us. c. The star is getting colder. d. The star is getting hotter.
a
No object produces a perfect thermal radiation spectrum, but many objects produce close approximations. Which of the following would not produce a close approximation to a thermal radiation spectrum a. a hot, thin (low-density, nearly transparent) gas b. a filament in a standard (incandescent) light bulb c. you d. a star
a
On average, approximately how fast do plates move with plate tectonics on Earth? a. a few centimeters per year b. They do not move at all, except during earthquakes. c. a few kilometers per hour d. a few centimeters per century e. a few millimeters per century
a
Rovers sent to Mars have discovered a. minerals in Martian rocks that can only form in liquid water. b. small pockets of liquid water lying just beneath the Martian soil. c. Mars has more craters than previously thought. d. clear evidence that life once existed on Mars.
a
Suppose that two stars are identical in every way; for example, same distance, same mass, same temperature, same chemical composition, and same speed relative to Earth, except that one star rotates faster than the other. Spectroscopically, how could you tell the stars apart a. The faster rotating star has wider spectral lines than the slower rotating star. b. The peak of thermal emission will be at a shorter wavelength for the faster rotating star than for the slower rotating star. c. There is no way to tell the stars apart spectroscopically because their spectra will be identical. d. The faster rotating star will have an emission line spectrum whereas the slower rotating star will have an absorption line spectrum.
a
Suppose the angular separation of two stars is smaller than the angular resolution of your eyes. How will the stars appear to your eyes? a. The two stars will look like a single point of light. b. You will see two distinct stars. c. The two stars will appear to be touching, looking rather like a small dumbbell. d. You will see only the larger of the two stars, not the smaller one. e. You will not be able to see these two stars at all.
a
Suppose you know the frequency of a photon and the speed of light. What else can you determine about the photon? a. its wavelength and energy b. its acceleration c. the chemical composition of the object that emitted it d. its temperature
a
Suppose you watch a leaf bobbing up and down as ripples pass it by in a pond. You notice that it does two full up and down bobs each second. Which statement is true of the ripples on the pond? a. They have a frequency of 2 hertz. b. They have a frequency of 4 hertz. c. They have a wavelength of two cycles per second. d. We can calculate the wavelength of the ripples from their frequency.
a
The angular separation of two stars is 0.1 arcseconds and you photograph them with a telescope that has an angular resolution of 1 arcsecond. What will you see? a. The photo will seem to show only one star rather than two. b. You will see two distinct stars in your photograph. c. The stars will not show up at all in your photograph. d. The two stars will appear to be touching, looking rather like a small dumbbell.
a
The choices describe four hypothetical planets. Which one would you expect to have the hottest interior? (Assume the planets orbit a star just like the Sun and that they are all the same age as the planets in our solar system.) a. Size: twice as big as EarthDistance from Sun: same as MercuryRotation rate: once every 6 months b. Size: same as the MoonDistance from Sun: same as MarsRotation rate: once every 10 days c. Size: same as VenusDistance from Sun: same as MarsRotation rate: once every 25 hours d. Size: same as MarsDistance from Sun: same as EarthRotation rate: once every 18 hours
a
The idea that energy in atoms has distinct energy levels is part of the branch of physics that is called a. quantum physics. b. special relativity. c. classical physics. d. particle physics. e. general relativity.
a
The nebular theory predicts that the young Sun should have been rotating quite rapidly, but the Sun rotates slowly today. Can this fact be explained by the nebular theory? a. Yes; the young Sun's solar wind would have carried away angular momentum, slowing the Sun's rotation. b. Yes, objects always slow their rotations over time. c. No, it is a complete mystery as to why the Sun would rotate slowly today.
a
The spectra of most galaxies show redshifts. This means that their spectral lines a. have wavelengths that are longer than normal. b. have wavelengths that are shorter than normal. c. always are in the red part of the visible spectrum. d. have a higher intensity in the red part of the spectrum.
a
What does angular resolution measure? a. the angular size of the smallest features that the telescope can see b. the size of an image c. the number of electromagnetic waves captured by an image d. the brightness of an image
a
What is meant by spectral resolution? a. It is a measure of how close two spectral lines can be and still be distinguishable. b. It is a measure of how close two stars can be in the sky and still be distinguishable. c. It is the same as angular resolution but applied to telescopes operating at different wavelengths. d. It is a measure of how much energy an object emits in different parts of the electromagnetic spectrum.
a
What is the Kuiper belt? a. a region of the solar system beginning just beyond the orbit of Neptune that contains many icy comets b. the most prominent ring of Saturn that is visible in photographs a technical name for the asteroid belt c. a region of the solar system that extends almost a fourth of the way to the nearest stars and contains a trillion comets with orbits going in all directions around the Sun
a
What is the purpose of the lens in an eye? a. to bend light entering the eye so that it is focused onto the retina to collect light to send to the brain to be interpreted b. to determine what color the eye will be c. to adjust the amount of light entering the eye so it is not too much or too little d. to interpret the light collected by the eye as colors
a
Which forms of light are lower in energy and frequency than the light that our eyes can see? a. infrared and radio b. ultraviolet and x-rays c. infrared and ultraviolet d. visible light
a
Which of the following best described the major ingredients of the jovian planets? a. hydrogen, helium, and hydrogen compounds b. rock and metal c. hydrogen and helium only d. rocky minerals and water e. hydrogen compounds and carbon dioxide
a
Which of the following best describes convection? a. Warm material expands and rises while cool material contracts and falls. b. Rocks sink in water. c. Bubbles of gas move upward through a liquid of the same temperature. d. A liquid separates according to density, such as oil and water separating in a jar. e. Warm material gets even warmer and cool material gets even cooler.
a
Which of the following best describes why radio telescopes are generally much larger in size than telescopes designed to collect visible light? a. Getting an image of the same angular resolution requires a much larger telescope for radio waves than for visible light. b. It is because radio telescopes are used in the daytime and visible light telescopes are used at night. c. Objects that emit radio waves are always much larger than objects that emit visible light, and therefore require larger telescopes. d. Radio telescopes are designed to collect sound rather than light.
a
Which of the following best describes why we say that light is an electromagnetic wave? a. The passage of a light wave can cause electrically charged particles to move up and down. b. The term electromagnetic wave arose for historical reasons, but we now know that light has nothing to do with either electricity or magnetism. c. Light is produced only when massive fields of electric and magnetic energy collide with one another. d. Light can be produced only by electric or magnetic appliances.
a
Which of the following conditions lead you to see an absorption line spectrum from a cloud of gas in interstellar space? a. The cloud is cool and lies between you and a hot star. b. The cloud is cool and dense, so that you cannot see any objects that lie behind it. c. The cloud is extremely hot. d. The cloud is visible primarily because it reflects light from nearby stars.
a
Which of the following could explain why Venus does not have a strong magnetic field? a. Its rotation is too slow. b. It has too thick an atmosphere. c. It does not have a metallic core. d. It is too close to the Sun. e. It is too large.
a
Which of the following could not be determined by an observation that only uses spectroscopy? a. the angular size of a distant galaxy b. the speed at which a distant galaxy is moving away from us c. the surface temperature of a distant star d. the chemical composition of a distant star e. the rotation rate of a distant star
a
Which of the following is not a major difference between the terrestrial and jovian planets in our solar system? a. Terrestrial planets contain large quantities of ice and jovian planets do not. b. Terrestrial planets orbit much closer to the Sun than jovian planets. c. Jovian planets have rings and terrestrial planets do not. d. Terrestrial planets are higher in average density than jovian planets.
a
Which of the following lists the ingredients of the solar nebula from highest to lowest percentage of mass of the nebula? a. hydrogen and helium gas, hydrogen compounds, rocks, metals b. hydrogen compounds, hydrogen and helium gas, metals, rocks c. hydrogen and helium gas, hydrogen compounds, metals, rocks d. hydrogen compounds, hydrogen and helium gas, rocks, metals e. hydrogen compounds, rocks, metals, hydrogen and helium gas
a
Which of the following observational techniques is most appropriate for measuring Doppler shifts? a. spectroscopy (taking a spectrum) b. imaging (taking a picture) c. timing (measuring how the amount of light changes with time)
a
Which of the following statements about electrons is not true? a. Electrons orbit the nucleus rather like planets orbiting the Sun. b. Electrons can jump between energy levels in an atom only if they receive or give up an amount of energy equal to the difference in energy between the energy levels. c. Within an atom, an electron can have only particular energies. d. An electron has a negative electrical charge. e. Electrons have little mass compared to protons or neutrons.
a
Which of the following wavelength regions can be studied with telescopes on the ground? a. radio, visible, and very limited portions of the infrared and ultraviolet regions b. all light with wavelengths longer than ultraviolet wavelengths c. all light with wavelengths shorter than infrared wavelengths e. infrared, visible, and ultraviolet light
a
Which of the following worlds show evidence of dried up rivers and lake beds? a. Mars b. Mercury c. Venus d. the Moon
a
Which planet experiences the strongest gravitational force from the Sun? a. Mercury b. Saturn c. Earth d. Jupiter e. Neptune
a
Which planet is orbited by the four "Galilean moons" known individually as Io, Europa, Ganymede, and Callisto? a. Jupiter b. Neptune c. Saturn d. Uranus e. Mars
a
Which two geological processes appear to have been most important in shaping the present surface of Venus? a. volcanoes and tectonics b. volcanoes and erosion c. impacts and volcanoes d. impacts and tectonics e. tectonics and erosion
a
A red shirt is red because it a. emits red light only. b. reflects red light but absorbs other colors. c. transmits red light. d. absorbs red light but reflects other colors.
b
Why did terrestrial planets form in the inner solar system and jovian planets in the outer solar system? a. In the inner part of the nebula, only metals and rocks were able to condense because of the high temperatures, whereas hydrogen compounds, although more abundant, were only able to condense in the cooler outer regions. b. Denser, heavier materials, such as rocks and metals, settled to the center of the nebula, and therefore, planets that formed there were more likely to be made primarily from rock and metal. c. As the solar nebula shrank, it settled into a spinning disk and separated into individual planets.
a
Why has NASA sent recent orbiters to Mars on trajectories that required them to skim through Mars's atmosphere before settling into their final orbits? a. It saves money because the spacecraft uses atmospheric drag to slow down rather than needing to carry enough fuel to slow by firing rocket engines. b. It allowed the orbiters to get higher resolution pictures of the surface as it came close when skimming through the atmosphere. Each spacecraft also carried a lander, and the lander could only be dropped to the Martian surface when the spacecraft passed through the atmosphere. c. It allowed the spacecraft to collect samples of the atmospheric gas for return to Earth.
a
Why would it not be a good idea to send a lander to one of the jovian planets? a. The jovian planets have no solid surface to land on. b. There's too much risk of hitting a boulder in the planet's rings on the way down. c. The jovian planets are too far away. d. It would be impossible to slow the lander down sufficiently to avoid a catastrophic crash. e. There is nothing interesting to find on the jovian planets.
a
In essence, the nebular theory holds that a. our solar system formed from the collapse of an interstellar cloud of gas and dust. b. the planets formed as a result of a near-collision between our Sun and another star. c. the planets each formed from the collapse of its own separate nebula. d. nebulae are clouds of gas and dust in space.
a.
A planet is most likely to have volcanic and tectonic activity if it has a. high surface gravity. b. high internal temperature. c. a dense atmosphere. d. low surface gravity. e. low internal temperature.
b
According to our theory of solar system formation, why does the Sun rotate slowly today? a. The Sun once rotated much faster, but it transferred angular momentum to the planets during the parts of their orbits where they come closest to the Sun. b. The Sun once rotated much faster, but it transferred angular momentum to charged particles caught in its magnetic field and then blew the particles away with its strong solar wind. c. The Sun once rotated much faster, but it lost angular momentum due to internal friction. d. The Sun once rotated much faster, but it lost angular momentum because everything slows down with time. e. The Sun was born rotating slowly because the solar nebula had very little angular momentum.
b
All of the following statements about the Sun's corona are true. Which one explains why it is a source of X-rays? a. The corona's structure is largely shaped by magnetic fields. b. The temperature of the corona's gas is some 1 to 2 million Kelvin. c. The corona's gas consists mostly of hydrogen and helium. d. The corona lies above the visible surface of the Sun.
b
An electron in an atom can go from a lower energy level to a higher energy level if the atom a. absorbs a photon of any wavelength. b. absorbs a photon of a specific wavelength. c. emits a photon of a specific wavelength. d. emits several photons of a specific wavelength. e. emits a photon of any wavelength.
b
Betelgeuse is the bright red star representing the left shoulder of the constellation Orion. All the following statements about Betelgeuse are true. Which one can you infer from its red color? a. It is much brighter than the Sun. b. Its surface is cooler than the surface of the Sun. c. It is much more massive than the Sun. d. It is moving away from us.
b
Everything looks red through a red filter because a. the filter reflects red light and transmits other colors. b. the filter transmits red light and absorbs other colors. c. the filter absorbs red light and emits other colors. d. the filter emits red light and absorbs other colors.
b
How does the spectrum of a molecule differ from the spectrum of an atom? a. Molecules only have spectral lines at ultraviolet wavelengths. b. A molecule has additional spectral lines due to changes in its rotational and vibrational energies. c. A molecule does not have spectral lines due to electrons changing energy levels. d. An atom has a wider range of spectral lines than molecules. e. Most atoms only have spectral lines at infrared wavelengths.
b
How much of the solar system's total mass is contained in the Sun? a. about 90% b. about 99.8% c. exactly 100% d. about half e. about 95%
b
If a hydrogen emission line appears at 656 nm in the laboratory, what can we say about a cloud of hydrogen gas, with an emission line at 680 nm? a. It is moving toward us. b. It is receding away from us. c. There is not enough information to say anything about the cloud's motion. d. It is neither receding nor approaching us.
b
Photons behave like a. waves. b. both waves and particles. c. particles. d. neither waves nor particles.
b
Studying a spectrum from a star can tell us a lot. All of the following statements are true except one. Which statement is not true? a. Shifts in the wavelengths of spectral lines compared to the wavelengths of those same lines measured in a laboratory on Earth can tell us the star's speed toward or away from us. b. The total amount of light in the spectrum tells us the star's radius. c. The peak of the star's thermal emission tells us its temperature; hotter stars peak at shorter (bluer) wavelengths. d. We can identify chemical elements present in the star by recognizing patterns of spectral lines that correspond to particular chemicals.
b
Suppose the Sun had been born with less mass, making it a smaller, cooler star. Which of the following consequences would we expect according to the nebular theory? a. The planets would have formed just as they did for our actual Sun, but the weaker gravity of a smaller Sun would have allowed the planets to escape into interstellar space. b. The frost line would have been closer to the Sun, so jovian planets could form at nearer distances than in our solar system. c. The frost line would have been farther from the Sun, so jovian planets could form only at greater distances than in our solar system. d. There would have been no solar nebula in which material could condense to form planets.
b
Thermal radiation is defined as a. radiation that is felt as heat. b. radiation with a spectrum whose shape depends only on the temperature of the emitting object. c. radiation in the form of emission lines from an object. d. radiation produced by an extremely hot object.
b
We can see other people because people a. emit infrared light. b. reflect visible light. c. reflect infrared light. d. emit visible light. e. emit thermal radiation.
b
We know that Earth has water. However, according to our theory of solar system formation, the inner solar system was too hot for hydrogen compounds like water to condense. What do we conclude? a. Earth's water probably originated through chemical reactions among the rock and metal of Earth's interior. b. Earth's water likely was brought here by asteroids or comets that formed beyond the frost line. c. Water arrived on Earth at a time when it rained throughout the inner solar system. d. Our theory of solar system formation will need modification because it is unable to account for the existence of water on Earth.
b
What does the technique of interferometry allow? a. It allows us to determine the chemical composition of stars. b. It allows two or more telescopes to obtain the angular resolution of a single telescope much larger than any of the individual telescopes. c. It allows the same telescope to make images with both radio waves and visible light. d. It allows astronomers to make astronomical observations without interference from light pollution. e. It allows two or more telescopes to obtain a total light-collecting area much larger than the total light-collecting area of the individual telescopes.
b
What is the best reason to put a visible-light telescope in space instead of on the ground? a. It is easier to launch very large space telescopes into space than to find places for them on the ground. b. The telescope is above the atmosphere so the light does not get distorted by turbulent air. c. A space telescope is closer to the source of the light, so it can make a clearer image. d. Space telescopes are not affected by earthquakes.
b
What is the giant impact hypothesis for the origin of the Moon? a. The Moon originally was about the same size as Earth, but a giant impact blasted most of it away so that it ended up much smaller than Earth. b. The Moon formed from material blasted out of Earth's mantle and crust by the impact of a Mars-size object. c. The Moon formed just like Earth, from accretion in the solar nebula. d. The Moon formed when two gigantic asteroids collided with one another.
b
What is the half-life of a radioactive isotope? a. half of the total time that the isotope has been in existence b. the amount of time for half of a sample of the isotope to decay into c. a different element or isotope d. half of the amount of that element in the universe e. the amount of time for half of a sample of the element to decay into nothing f. half of the age of the solar system
b
What is the main factor that makes Earth more geologically active than the other terrestrial planets? a. It has far more radioactive material than other planets. b. It is larger, so it has retained its internal heat for longer. c. It is farthest from the Sun, so it receives less light. d. It formed much later than the other planets. e. It has a large Moon, so it is heated by tidal forces.
b
What is the purpose of adaptive optics? a. It allows several small telescopes to work together like a single larger telescope. b. It reduces blurring caused by atmospheric turbulence for telescopes on the ground. c. It is a special technology that allows the Hubble Space Telescope to adapt to study many different types of astronomical objects. d. It allows ground-based telescopes to observe ultraviolet light that normally does not penetrate the atmosphere.
b
When your eye forms an image, the ________ plays a role analogous to the detector in a camera. a. pupil b. retina c. lens d. optic nerve
b
Which of the following could explain why Venus does not have a strong magnetic field? a. It does not have a metallic core. b. Its rotation is too slow. c. It has too thick an atmosphere. d. It is too large. e. It is too close to the Sun.
b
Which of the following is a feature of our solar system that should be predicted by a successful theory of solar system formation? a. the fact that Earth has a 23-1/2° axis tilt b. the fact that all the planets in our solar system orbit the Sun in the same direction c. the fact that Jupiter has the most known moons in the solar system the age of our solar system d. the fact that there are exactly four terrestrial planets and exactly four jovian planets
b
Which of the following is not a line of evidence supporting the hypothesis that our Moon formed as a result of a giant impact? a. The Moon's average density suggests it is made of rock much more like that of the Earth's outer layers than that of the Earth as a whole. b. The Pacific Ocean appears to be a large crater, probably the one made by the giant impact. c. The Moon has a much smaller proportion of easily vaporized materials than Earth. d. Computer simulations show that the Moon could really have formed through a giant impact.
b
Which of the following is not a major pattern of motion in the solar system? a. The Sun and most of the planets rotate in the same direction in which the planets orbit the Sun. b. Nearly all comets orbit the Sun in same direction and roughly the same plane. c. Most of the solar system's large moons orbit in their planet's equatorial plane. d. All of the planets orbit the Sun in the same direction; counterclockwise as viewed from above Earth's north pole.
b
Which of the following objects would produce an emission line spectrum? a. a star like our Sun b. a hot, low-density neon gas c. the Earth d. a light bulb
b
Which of the following observations of an extrasolar planet system would be inconsistent with what we expect from the nebular theory of solar system formation? a. a system in which some planets rotate in a direction opposite to their orbits b. a system in which all the planets orbit in completely different planes c. a system which has two terrestrial planets close in and two jovian planets farther out d. a system in which some planets have small moons orbiting in a direction opposite to the planet's rotation
b
Which of the following stars is the hottest? a. a green star b. a blue star c. an orange star d. a yellow star e. a red star
b
Which of the following statements best describes the difference between a refracting telescope and a reflecting telescope? a. A refracting telescope produces refracted images, whereas a reflecting telescope produces reflected images. b. A refracting telescope uses a transparent glass lens to focus light, whereas a reflecting telescope uses a mirror to focus light. c. Reflecting telescopes make much clearer images than refracting telescopes of the same size. d. It is much easier to make a large refracting telescope than a large reflecting telescope.
b
Which of the following statements best explains why all the planets orbit the Sun in the same direction and in nearly the same plane? a. No one knows: planets form randomly, so it's a puzzle why they orbit with such a pattern. b. The planets formed from a disk of rotating gas, and their orbits therefore orbit as this gas did. c. The Sun's rotation spun out the planets as it formed. d. The Sun's gravity is strongest as its equator, so it pulled all the planets into this orbital alignment.
b
Which planet has the highest average surface temperature and why? a. Mercury, because of its dense carbon dioxide atmosphere b. Venus, because of its dense carbon dioxide atmosphere c. Jupiter, because it is so big d. Mercury, because it is closest to the Sun e. Mars, because of its red color
b
Which planet has the most extreme differences between its daytime and nighttime temperatures? a. Venus b. Mercury c. Earth d. Jupiter e. Mars
b
Why does the Sun's image look distorted in shape at sunset? a. Air scatters different colors of light by different amounts. b. The distortion arises because of the way air affects the paths of light. c. The distortion is an artifact of the photographic process that your eyes would not actually see. d. The distortion is an illusion that you notice by eye but does not show up in photographs.
b
You observe a distant galaxy. You find that a spectral line of hydrogen that is shifted from its normal location in the visible part of the spectrum into the infrared part of the spectrum. What can you conclude? a. The galaxy is moving toward you. b. The galaxy is moving away from you. c. The galaxy is made purely of hydrogen. d. The galaxy has weak gravity.
b
According to our basic scenario of solar system formation, why do the jovian planets have numerous large moons? a. The many moons of the jovian planets remains one of the unexplained mysteries of the formation of our solar system. b. The large moons of the jovian planets originally formed in the inner solar system and these moons then migrated out to join up with the jovian planets. c. As the growing jovian planets captured gas from the solar nebula, the gas formed swirling disks around them, and moons formed from condensation accretion within these disks. d. Because of their strong gravity, the jovian planets were able to capture numerous asteroids that happened to be passing nearby, and these became the major moons of the jovian planets.
c
According to our theory of solar system formation, which law best explains why the solar nebula spun faster as it shrank in size? a. Einstein's law that E = mc2 b. the law of universal gravitation c. the law of conservation of angular momentum d. Kepler's first law of planetary motion
c
All the following statements about Venus are true. Which one offers evidence of a global repaving about a billion years ago? a. Venus has many circular features, called coronae, which appear to be tectonic in origin. b. Venus appears to lack any water that could lubricate the flow of rock in its crust and mantle. c. Venus has relatively few impact craters and these craters are distributed fairly evenly over the entire planet. d. Venus's largest features are three elevated regions that look somewhat like continents.
c
Comets are made mostly of a. hydrogen gas. b. rock. c. rock and ice. d. metal. e. rock and metal.
c
How does the light-collecting area of a telescope with a 10-meter diameter mirror compare to that of a telescope with a 5-meter diameter mirror? a. The 10-meter telescope has 2 times the light collecting area. b. The 10-meter telescope has 10 times the light collecting area. c. The 10-meter telescope has 4 times the light collecting area.
c
One star is emitting primarily visible light, and another star is emitting primarily infrared light. Which star is hotter? a. The star emitting infrared light is hotter. b. Both stars are the same temperature. c. The star emitting visible light is hotter. d. There is not enough information to answer the question.
c
Suppose you have two small photographs of the Moon. Although both look the same at small size, when you blow them up to poster size one of them still looks sharp, while the other one becomes fuzzy (grainy) looking. Which of the following statements is true? a. Both photographs have the same angular resolution because they are both photographs of the same object. b. The one that looks fuzzy at large size has better angular resolution (smaller) than the one that looks sharp. c. The one that still looks sharp at large size has better (smaller) angular resolution than the one that looks fuzzy. d. Both photographs have the same angular resolution because they were both printed at the same sizes in each case.
c
Vaporization is the process in which a. molecules go from the solid phase to the liquid phase. b. electrons are stripped from atoms. c. molecules go from the liquid or solid phase to the gas phase. d. molecules go from the liquid phase to the solid phase.
c
What causes stars to twinkle? a. the inability of the human eye to focus on small points of light b. variable absorption by interstellar gas along the line of sight to the star c. bending of light rays by turbulent motions of air in Earth's atmosphere d. It is intrinsic to the stars—their brightness varies as they expand and contract. e. variations in the absorption of light at different depths in Earth's atmosphere
c
What is our best hypothesis for why all the planets in our solar system orbit in the same direction as the Sun rotates? a. Almost everything in our Galaxy rotates in the same direction. b. The planets were pulled out of the Sun by a major interaction with another star. c. The planets and Sun formed from the same, single, rotating gas cloud. d. It's a complete coincidence. e. The Sun did not initially rotate, but the planets gravity caused it to start rotating in the direction in which the planets orbit.
c
What is the Kuiper belt? a. a technical name for the asteroid belt b. a region of the solar system that extends almost a fourth of the way to the nearest stars and contains a trillion comets with orbits going in all directions around the Sun c. a region of the solar system beginning just beyond the orbit of Neptune that contains many icy comets d. the most prominent ring of Saturn that is visible in photographs
c
When your eye forms an image, the ________ plays a role analogous to the detector in a camera. a. optic nerve b. lens c. retina d. pupil
c
Where does nuclear fusion occur in the Sun? a. in a layer just above the visible surface b. in a layer just below the surface c. deep in its core d. on the surface
c
Which of the following best describes the fundamental difference between two different chemical elements (such as oxygen and carbon)? a. They have different atomic mass numbers. b. They have different numbers of electrons. c. They have different numbers of protons in their nucleus. d. They have different names.
c
Which of the following best describes the lunar maria? a. densely cratered regions on the Moon b. frozen oceans of liquid water on the Moon c. relatively smooth, flat plains on the Moon d. mountainous regions on the Moon
c
Which of the following is not a characteristic of all the terrestrial planets? a. They have solid, rocky surfaces. b. They are located closer to the Sun than the jovian planets. c. They have substantial atmospheres. d. They have higher densities than the jovian planets. e. They are smaller than the jovian planets.
c
Which of the following statements best describes the two principle advantages of telescopes over eyes? a. Telescopes have much more magnification and better angular resolution. b. Telescopes collect more light and are unaffected by twinkling. c. Telescopes can collect far more light with far better angular resolution. d. Telescopes can collect far more light with far greater magnification.
c
Which of the following telescopes benefits most from adaptive optics? a. the Chandra X-ray Observatory b. the Arecibo radio telescope in Puerto Rico c. the Keck I telescope on Mauna Kea d. the Hubble Space telescope
c
Which statement about photons is true? a. An infrared photon has less energy than an x-ray photon, and travels more slowly. b. An infrared photon has more energy than an x-ray photon, but travels at the same speed. c. An infrared photon has less energy than an x-ray photon, but travels at the same speed. d. An infrared photon has more energy than an x-ray photon, and travels more quickly.
c
Why are there fewer large impact craters on Earth's seafloor than on the continents? a. Erosion erases impact craters must faster on the ocean bottom than on land. b. Most impacts occur on the land. c. Seafloor crust is younger than continental crust, so it has had less time in which to suffer impacts. d. The oceans slow large impactors and prevent them from making craters.
c
Why is Earth's continental crust lower in density than seafloor crust? a. Continental crust is made from the volcanic rock called basalt. b. Continental crust comes from Earth's inner core, while seafloor crust comes from the outer core. c. Continental crust is made as the lowest-density seafloor crust melts and erupts to the surface near subduction zones. d. Continental crust comes from volcanoes, while seafloor crust comes from geysers.
c
According to our theory of solar system formation, what are asteroids and comets? a. chunks of rock or ice that were expelled from planets by volcanoes b. the shattered remains of collisions between planets c. chunks of rock or ice that condensed after the planets and moons finished forming d. leftover planetesimals that never accreted into planets
d
Astronomers sometimes make use of "neutrino telescopes," which are typically located deep underground. What are neutrinos? a. a very low-energy form of light b. a type of wave predicted to exist by Einstein's general theory of relativity c. a very high-energy form of light d. a type of light-weight subatomic particle
d
Betelgeuse is the bright red star representing the left shoulder of the constellation Orion. All the following statements about Betelgeuse are true. Which one can you infer from its red color? a. It is much brighter than the Sun. b. It is much more massive than the Sun. c. It is moving away from us. d. Its surface is cooler than the surface of the Sun.
d
Deep trenches in the ocean mark places where a. hot mantle material rises upward and spreads sideways, pushing the plates apart. b. plates pull apart, leaving great rifts in the crust. c. plates push together, creating ocean mountain chains. d. one plate slides under another, returning older crust to the mantle. e. plates slip sideways relative to one another.
d
Earth's atmosphere is most transparent to all wavelengths of ________ light. a. infrared b. ultraviolet c. x-ray d. visible
d
Grass appears green because a. it emits green light and absorbs other colors. b. it absorbs green light and emits other colors. c. it transmits green light and emits other colors. d. it reflects green light and absorbs other colors.
d
If one object has a large redshift and another object has a small redshift, what can we conclude about these two objects? a. The one with the large redshift is hotter and therefore is putting out more radiation. b. The one with the large redshift is moving away from us, and the one with the small redshift is moving toward us. c. The one with the large redshift is redder in color than the other one. d. The one with the large redshift is moving away from us faster than the one with the small redshift. e. The one with the large redshift is moving toward us faster than the one with the small redshift.
d
In which of the following ways are Pluto and Eris more like comets than like any of the terrestrial or jovian planets? a. They sometimes enter the inner solar system. b. They have long tails. c. They have thick atmospheres. d. They are made mostly of rock and ice.
d
Other than Earth, which of the following has visible polar caps? a. Jupiter b. The Moon c. Venus d. Mars e. Mercury
d
Oxygen has atomic number 8. How many times must an oxygen atom be ionized to create an O+5 ion, and how many electrons will the ion have? a. It must be ionized five times; it will have five electrons. b. It doesn't have to be ionized; it already has only three electrons. c. It doesn't have to be ionized; it just needs to gain five protons. d. It must be ionized five times; it will have three electrons. e. It must be ionized three times; it will have five electrons.
d
Radio telescopes are generally ________ than visible-light telescopes. a. much more expensive b. located at much higher altitudes c. much smaller d. much larger
d
What do we mean by the frost line when we discuss the formation of planets in the solar nebula? a. It is another way of stating the temperature at which water freezes into ice. b. It marks the special distance from the Sun at which hydrogen compounds become abundant; closer to the Sun, there are no hydrogen compounds. c. It is the altitude in a planet's atmosphere at which snow can form. d. It is a particular distance from the Sun, beyond which the temperature was low enough for ices to condense.
d
What do we mean when we say that the terrestrial worlds underwent differentiation? a. Their surfaces show a variety of different geological features resulting from different geological processes. b. They lost interior heat to outer space. c. The five terrestrial worlds all started similarly but ended up looking quite different. d. When their interiors were molten, denser materials sank toward their centers and lighter materials rose toward their surfaces.
d
What happened during the heavy bombardment? a. Planetesimals collided with one another and stuck together to form planets. b. The planets collided with one another. c. A supernova disrupted a gas cloud, causing it to start collapsing to form the solar system. d. The planets of the solar system suffered many impacts. e. A large meteor collided with Earth, killing the dinosaurs.
d
What is the difference between energy and power? a. Power is used to describe energy of light, whereas the term energy has a broader meaning. b. There's no difference; energy and power are different names for the same thing. c. Power is measured in joules and energy is measured in watts. d. Power is the rate at which energy is used, so its units are a unit of energy divided by a unit of time.
d
When an atom's electrons fall down to lower energy levels in a thin cloud of hot gas, what is produced? a. an infrared spectrum b. thermal radiation c. an absorption line spectrum d. an emission line spectrum e. new interstellar compounds
d
Which internal heat source still generates heat within the terrestrial worlds today? a. heat from convection b. heat of accretion c. heat from differentiation d. heat from radioactive decay
d
Which of the following factors was very important to the decision to classify Pluto as a dwarf planet rather than a "regular" planet? a. its composition of ice and rock b. its relatively large moon, Charon c. its large distance from the Sun d. its small size and mass
d
Which of the following is NOT a pattern of motion in our Solar System? a. Most planetary orbits lie in the same plane. b. Most planets rotate in the same direction they orbit. c. Almost all large moons orbit their planet in the same direction as the planet's rotation. d. The planets orbit the Sun in a direction opposite that of the Sun's rotation. e. Most planets orbit in the same direction.
d
Which of the following is not a good reason to place an observatory on a remote mountain to? a. reduce the impact of light pollution b. reduce the twinkling caused by Earth's atmosphere c. allow study of infrared light d. allow observations at ultraviolet and x-ray wavelengths
d
Which of the following is not an advantage of the Hubble Space Telescope over ground-based telescopes? a. It can observe infrared and ultraviolet light, as well as visible light. b. It never has to close because of cloudy skies. c. Stars do not twinkle when observed from space. d. It is closer to the stars.
d
Which of the following is the underlying reason why Venus has so little wind erosion? a. its relatively close distance to the Sun b. its small size c. its thick atmosphere d. its slow rotation
d
Which of the following statements about Pluto is true? a. It is orbited by only one moon. b. It is the most massive object that orbits the Sun beyond the orbit of Neptune. c. It is the only object in our solar system that is categorized as a "dwarf planet." d. It has more in common with other icy objects in the Kuiper belt than it does with the jovian planets (Jupiter, Saturn, Uranus, Neptune).
d
Which of the following statements about thermal radiation is always true? a. A hot object emits less total radiation than a cool object. b. A hot object emits more radio waves than a cool object. c. A hot object emits more total radiation than a cool object. d. A hot object emits more total radiation per unit surface area than a cool object. e. A hot object emits more x-rays than a cool object.
d
Which of the following statements about x-rays and radio waves is not true? a. X-rays have higher frequency than radio waves. b. X-rays and radio waves are both forms of light, or electromagnetic radiation. c. X-rays have shorter wavelengths than radio waves. d. X-rays travel through space faster than radio waves.
d
Which of the following would be the most useful ultraviolet telescope? a. a 10-meter telescope on a mountain b. a 1-meter telescope in space c. a 30-meter telescope on a mountain d. a 2.5-meter telescope in space
d
Which two factors are most important to the existence of plate tectonics on Earth? a. the existence of life and oxygen in the atmosphere b. Earth's liquid outer core and solid inner core c. oxygen in the atmosphere and mantle convection d. mantle convection and a thin lithosphere
d
Why can't we see radio waves? a. Radio waves have too low energy to be detected by any means. b. Radio waves are sound waves, so we hear them. c. Radio waves fade away before they can reach our eyes. d. Radio waves have wavelengths too long for the eye to detect. e. We do see radio waves, but we interpret them as the color red.
d
An electron-volt is a. the charge of one electron. b. an amount of energy much larger than a joule. c. the energy jump between the first and second energy levels of hydrogen. d. the energy of one electron. e. an amount of energy much smaller than a joule.
e
How does the spectrum of a molecule differ from the spectrum of an atom? a. An atom has a wider range of spectral lines than molecules. b. A molecule does not have spectral lines due to electrons changing energy levels. c. Molecules only have spectral lines at ultraviolet wavelengths. d. Most atoms only have spectral lines at infrared wavelengths. e. A molecule has additional spectral lines due to changes in its rotational and vibrational energies.
e
If an interstellar gas cloud shrinks in size, what does the law of conservation of energy predict it will do? a. cool off b. spin faster c. spin slower d. continue shrinking e. heat up
e
If two objects are the same size, but one object has a temperature 3 times as hot (in Kelvin) as the other object, the hotter object emits a. 12 times as much energy. b. 27 times as much energy. c. 3 times as much energy. d. 9 times as much energy. e. 81 times as much energy.
e
If you want to see the image formed by a telescope, you should place your eye at the location of the telescope's a. Cassegrain. b. primary mirror. c. secondary mirror. d. central hole in the primary mirror. e. focus.
e
Molecular dissociation is the process in which a. the bonds between electrons around an atomic nucleus are broken. b. a molecule goes from the solid phase to the gas phase. c. an electron is shared between atomic nuclei. d. an element changes into another form. e. the bonds between atoms in a molecule are broken.
e
Spectra from neutral atoms compared with spectra from ionized atoms of the same element a. have the same sets of spectral lines but different widths for those lines. b. are the same. c. are slightly redshifted. d. are slightly blueshifted. e. have different sets of spectral lines.
e
The Oort cloud is a. the cloud of gas from which the solar system formed. b. a region in the same plane as the planets that contains hundreds of thousands of comets. c. a circular region between the orbits of Mars and Jupiter that contains most known asteroids. d. a vast cloud of gas that encircles the solar system at a great distance from the Sun. e. a roughly spherical region larger than the orbit of Pluto that may contain a trillion comets.
e
What happened during the accretion phase of the early solar system? a. Earth gained its oceans from icy planetesimal capture. b. Atoms of hydrogen and helium gas bonded together and solidified. c. The solar nebula differentiated into metals inside of the frost line and ices beyond. d. Large planetesimals captured atmospheres from the solar nebula. e. Particles grew by colliding and sticking together.
e
Which of the following best describes how and why x-ray telescopes differ from visible light telescopes? a. X-ray telescopes have to be built with very thick mirrors because x-ray photons will penetrate a thin mirror. b. X-ray telescopes do not use mirrors because x-ray photons cannot be focused. c. X-ray telescopes must be much larger because of the small number of x-ray photons. d. X-ray telescopes cannot do spectroscopy because all x-ray photons have the same wavelength. e. X-ray telescopes use grazing incidence mirrors because x-ray photons will penetrate a normal mirror.
e
Which of the following must be true for differentiation to occur in a planet? a. The planet must have an atmosphere. b. The planet must have a rocky surface. c. The planet must be made of both metal and rock. d. The planet must be geologically active, that is, have volcanoes, planetquakes, and erosion from weather. e. The planet must have a molten interior.
e
Which of the following objects does not produce a spectrum that is a close approximation to a thermal radiation spectrum? a. a planet b. a star c. a filament in an ordinary (incandescent) light bulb d. you e. a hot, transparent gas
e
Which statement correctly describes units that can be used to measure energy and power? a. Energy is measured in watts and power is measured in watts per second. b. Energy is measured in watts and power is measured in newtons. c. Energy and power are both measured in units of joules. d. Energy and power are both measured in units of watts. e. Energy is measured in joules and power is measured in joules per second.
e
Why does Earth have the strongest magnetic field among the terrestrial worlds? a. It is the most volcanically active world. b. It is the only one that has a metallic core. c. It is by far the largest terrestrial world. d. It rotates much faster than any other terrestrial world. e. It is the only one that has both a convecting core region and reasonably rapid rotation.
e