Course Review Notes
Chapter 1: Astronomy
1. The study of the universe is referred to as:
2. The distances to other stars beyond the Sun are measured in:
B) astronomical units.
C) light days.
D) light months.
E) light years.
3. Modern scientific theories are NOT:
B) continuously tested.
4. The greek scientist who applied the scientific method to lunar eclipses was:
5. Which of the following describes parallax?
A) It is best measured over exactly one year intervals.
B) It is inversely proportional to the distance to the star.
C) It was first observed by Galileo with his new telescope.
D) It is only applicable to objects within the solar system.
E) It is more accurate as the distances to objects becomes greater.
Chapter 2: Copernican Revolution
1) The most famous prehistoric astronomical observatory is:
A) the Sphinx.
C) Big Horn stone circle.
E) Mount Rushmore.
2. The Ptolemaic model of the universe:
A) explained and predicted the motions of the planets with deferents and epicycles.
B) is the basis of our modern cosmology.
C) could not account for the stellar parallax observed by Hipparchus.
D) describes the orbits of the planets as being ellipses, not circles.
E) always kept Mars and Mercury between the Earth and Sun.
3. The Ptolemaic model probably persisted for all these reasons EXCEPT:
A) it had the authority of Aristotle behind it.
B) it was consistent with the doctrines of the Catholic Church.
C) it used perfect circles, which appealed to geometry.
D) it accounted well for Galileo's observations of the phase cycle of Venus.
E) it explain why stellar parallax was not observed by the Greeks.
4. The greatest contribution of the Greeks to modern thought was:
A) the idea that all the planets orbited the Sun.
B) that their mythology was the basis for the naming of the constellations.
C) that their observation of stellar parallax proved the Earth orbited the Sun.
D) the development of scientific inquiry and model building.
E) the invention of the telescope.
5. On which of these assumptions do Ptolemy and Copernicus agree?
A) The Earth must be the center of all motion in the Cosmos.
B) All orbits must be perfect circles.
C) The Sun was bigger than the Earth.
D) Venus must always stay between us and the Sun.
E) The Sun must orbit us, but the planets do orbit the Sun.
6. The heliocentric model was actually first proposed by:
D) Alexander the Great.
7. Which of the following is a contribution to astronomy made by Galileo?
A) The astronomical telescope can show us far more detail than the eye can.
B) Jupiter has four moons orbiting it.
C) The Moon has craters, mountain, valleys, and dark flat areas on its surface.
D) Venus appears almost fully lit when it lies on the far side of the Sun.
E) All of the above are his discoveries.
8. Which of these was not seen telescopically by Galileo?
B) Venus' phase cycle
C) Four moons around Jupiter
D) stellar parallax
E) Craters and mare on the Moon
9 Which concept was NOT a part of Kepler's Laws of Planetary Motion?
A) All planetary orbits are ellipses.
B) The square of the planet's period is equal to the cube of its average distance.
C) A planet must move fastest in its orbit at perihelion.
D) Epicycles are needed to explain the varying brightnesses of the planets.
E) The line that connects the Sun to Mercury sweeps out the same area in a month as does the line connecting us to the Sun.
10. According to Kepler's third law, the square of the planet's period in years is:
A) equal to its perihelion distance from the Sun in A.U.
B) inversely proportional to its mass in kilograms.
C) equal to the fourth power of its average temperature in degrees Kelvin.
D) proportional to the cube of its semimajor axis in A.U.
E) equal to the square of its aphelion distance in A.U.
11. What contribution to astronomy was made by Tycho Brahe?
A) The planets' orbits around the Sun are ellipses, not circles.
B) The Earth is not the center of the Universe.
C) His observations of planetary motion with great accuracy proved circular orbits could not work.
D) His telescope revealed the moons of Jupiter before Galileo noted them.
E) Retrograde motion must be explained by epicycles larger than those of Ptolemy.
12. Upon which point do Copernicus and Kepler disagree?
A) The Moon orbits the Earth.
B) The Earth orbits the Sun.
C) Retrograde motion occurs when one planet overtakes another.
D) The orbits of the planets are ellipses, with one focus at the Sun.
E) Venus will appear as a crescent when she retrogrades between us and the Sun.
13. The Law of Universal Gravitation was developed by:
14. Which of these was a contribution of Newton to astronomy?
A) Artificial satellites could be put into orbit about the Earth.
B) The Sun's gravity is greatest on a planet at perihelion, so the planet must speed up.
C) The Moon pulls as strongly on us as we do on it.
D) His differential calculus lets us calculate planetary motions more accurately.
E) All of these were due to Newton's work.
15. The force of gravity between two objects:
A) increases with the masses of the bodies, but decreases with their separations.
B) increases with the masses of the bodies, but decreases with the square of the distances between them.
C) increases with the square of their masses, but decreases with the cube of their periods of orbit about the Sun.
D) depends on the density, not the mass of the bodies.
E) depends on the temperature, density, and size of the bodies.
Chapter 3: Information from Radiation
1. The number of waves passing the observer per second is:
A) the wavelength in angstroms.
B) the amplitude in nm.
C) the frequency in Hertz.
D) the period in seconds.
E) the energy in milliwatts.
2. The distance between successive wave crests defines the ________ of a wave.
3. Which of these is constant for all types of electromagnetic radiation in space?
4. Light waves differ fundamentally from water or sound waves because:
A) they do not require a material medium for transmission.
B) they have many different wavelengths.
C) they all have the same energy.
D) they can only travel at one speed, regardless of the medium.
E) the energy of all light waves is constant.
5. Radial motion can be revealed by spectroscopic analysis using the:
A) the Photoelectric Effect.
B) Newtonian Relativity.
C) the Doppler Effect.
D) Gravitational Redshift.
E) Stefan's Law.
6. If a light source is approaching you, you will observe:
A) an apparent red shift of its spectral lines.
B) that its light has become much bluer in color.
C) that all of its spectral lines have become shorter in wavelength.
D) that the amplitude of its waves have increased.
E) that the speed of its photons have increased.
Chapter 4: Spectroscopy
1. What is spectroscopy?
A) an analysis of the way in which atoms absorb and emit light
B) a study of the geometry of rainbows
C) an observational technique to measure the brightness of light at different colors
D) the use of CCDs to capture light more efficiently than with photographic film
E) a method to freeze atmospheric turbulence for better resolution
2. Typical stellar spectra appear as:
A) a series of bright, colored lines.
B) an unbroken rainbow of colors.
C) a rainbow, but with some dark lines mixed in.
D) a rainbow with some bright lines on top of the continuum.
E) a very red shifted rainbow due to the expansion of the universe.
3. The three laws dealing with the creation of various spectra are due to:
4. The classical model of the hydrogen atom that explains its spectral line structure is due to:
5. Spectral lines are often referred to as the stars' "fingerprints" because:
A) fingerprints also consist of individual lines that make a pattern.
B) both are unique to their source.
C) both can be easily categorized.
D) both are characteristic of the individual that produced them.
E) All of these are correct.
6. Einstein's Nobel Prize in Physics was actually awarded for his:
A) Special Theory of relativity.
B) General Theory of Relativity.
C) work on the photoelectric effect and the nature of electron orbitals.
D) work on the Manhattan Project and the atomic bomb.
E) discovery of the expansion of the universe.
Chapter 5: Telescopes
1. Why are most large telescopes reflectors, not refractors?
A) Large lenses deform under their own weight, but mirrors can be supported.
B) Large mirrors need only one optical surface, achromats four surfaces to grind.
C) Reflectors do not suffer from chromatic aberration like refractors do.
D) Large, very clear lenses are harder to cast than more tolerant mirror blanks.
E) All of the above are correct.
2. Which design has a convex primary mirror and flat secondary mirror, with the eyepiece located on the top side of the telescope tube?
B) Newtonian reflector
C) Cassegrain reflector
D) prime focus reflector
3. This design combines the radiation from two different scopes to greatly enhance resolution via computer synthesis.
A) Cassegrain reflector
B) Newtonian reflector
C) prime focus reflector
4. The tendency of a wave to bend as it passes from one transparent medium to another is called:
5. The process occurring when photons bounce off a polished surface is called:
6. Which branch of astronomy is focused on precise measurement of brightness?
7. The instrument that analyzes the colors and temperatures of stars best is a:
E) CCD imager.
8. What are two advantages of large scopes over smaller ones?
A) Large scopes have a larger field of view and sharper focus.
B) Large scopes are not subject to atmospheric turbulence and opacity like smaller ones.
C) Large scopes are easier to mount and control than small ones.
D) Large telescope have more light grasp and better resolution.
E) Large telescopes give higher magnification and are easier to build.
9. What is the resolving power of the telescope?
A) the ability to make distant objects appear closer
B) the ability to collect a lot of light
C) the ability to detect very faint objects
D) the ability to distinguish adjacent objects in the sky
E) the ability to separate light into its component colors
10. What is the primary purpose of an astronomical telescope?
A) To magnify and make distant objects appear closer.
B) To separate light into its component colors.
C) To measure the intensity of light very accurately.
D) To access wavelengths that we cannot see visually.
E) To collect a lot of light and bring it to a focus.
11. A mountain top is an especially good site for infrared telescopes since:
A) there you are closer to celestial objects.
B) you are above most of the carbon dioxide and water vapor in the atmosphere.
C) the cold weather helps the sensitivity of infrared detectors.
D) less air above means better seeing in many cases.
E) All of the above are factors.
12. Which of the following is a problem inherent in all large radio telescopes?
A) They are badly affected by poor seeing and atmospheric turbulence.
B) The lightest breeze shakes them, making the observations blurry.
C) Their waves are blocked by water vapor, so they must be located in deserts.
D) Radio waves have long wavelengths, so radio telescopes have poor resolution.
E) The dust clouds in the Milky Way block almost all wavelengths except light.
13. Radio dishes are large in order to:
A) attract funding from NASA and the NSF.
B) give greater magnification.
C) increase their angular resolution and collect the very weak radio photons.
D) increase the range of waves they can collect.
E) detect shorter waves than optical telescopes for superior resolution.
14. For what is an interferometer used?
A) to decrease the impact of poor seeing on telescope resolution
B) to increase the light grasp by combining the surface area of both scopes
C) to decrease the effects of light pollution on light grasp
D) to increase the sensitivity of infrared detectors
E) to improve the angular resolution of all types of telescopes
15. The name of the new Infrared Orbiting Observatory is the:
A) Hubble Space Telescope.
B) Compton Observatory.
C) Spitzer Space Telescope.
D) Chandra Orbiting Telescope.
E) Newton Imaging System.
Chapter 6: Comparative Planetology
1. Our understanding of the solar system has come in a way that can best be described as:
A) constant since prehistoric times.
B) slow and steady since the discovery of the telescope by Galileo.
C) erratic, with spurts when new planets were found.
D) steady until the last decade, when the decline in the space program slowed it a great deal.
E) explosive, with us learning more in the past few decades than in all previous history.
2. What is the goal of comparative planetology?
A) to use planetary positions to foretell the future
B) to find which planets will be most suitable for future colonization
C) to help plan future visits by unmanned probes, orbiters, and rovers
D) to determine the origin and evolution of the solar system
E) to find out how our own solar system compares with extrasolar ones
3. The plane in which almost all planets orbit the sun is called the:
A) equator of the solar system.
E) galactic plane.
4. Which of these is NOT a jovian planet?
5. Which of the following are terrestrial planets?
A) only Earth
B) the Earth, Moon, and Venus
C) Mercury, Venus, Earth, and Mars
D) Mercury, Venus, Earth, Moon, Mars, and Pluto
E) Mercury, Venus, Earth, Moon, Mars, and Ceres
6. Which of the following is NOT a way that terrestrial and jovian planets differ?
A) Spinning rapidly, jovians are more oblate than solid terrestrials.
B) Jovian orbits are more eccentric than terrestrials, and farther off the ecliptic.
C) Jovians have many more satellites than do terrestrials.
D) Jovians have rings, terrestrials don't.
E) Jovians are less dense than any of the terrestrials.
7. How do the densities of the jovian and terrestrial planets compare?
A) Made from the same solar nebula, they are all similar.
B) More massive jovians all have high densities, compared to the tiny terrestrials.
C) All terrestrials are more dense than any of the jovians.
D) The closer a planet lies to the Sun, the less its density.
E) No real pattern here; densities vary greatly and are very individual to each world.
8. In density and size, Pluto is most like a:
A) large asteroid.
B) jovian planet.
C) terrestrial planet.
D) large jovian moon.
E) small comet.
9. In composition and mass and density, Jupiter is most like:
A) a huge comet.
B) a gigantic asteroid.
C) the Sun.
D) a huge Kuiper belt Object.
E) a large terrestrial planet.
10. In composition and density, the asteroids most resemble:
B) the Sun.
C) jovian moons.
D) pieces of terrestrial planets.
E) Kuiper Belt objects like Pluto.
11. Which of the following falls into the category of interplanetary debris?
A) everything orbiting the Sun in the ecliptic plane
B) dust orbiting the Sun in the ecliptic plane, as seen around other young stars
C) large and small comets and asteroids and grains of dust
D) only the Kuiper Belt objects
E) only asteroids with orbits between 2-5 A.U.
12. Which statement about comets is NOT true?
A) Their orbits tend to be more eccentric than those of asteroids.
B) Their densities are higher than those of asteroids.
C) They tend to be made of ice that easily vaporizes near perihelion.
D) They look fuzzy, while asteroids appear as moving points of light.
E) Their average distances from the Sun are far greater than those of asteroids.
13. Most asteroids are found:
A) beyond the orbit of Neptune.
B) between the Earth and Sun.
C) between the orbits of Mars and Jupiter.
D) in the orbit of Jupiter, but 60 degrees ahead or behind it.
E) orbiting the jovian planets in captured, retrograde orbits.
14. A gravitational "sling-shot":
A) causes comets to crash into planets, such as Jupiter in 1994.
B) allowed the Apollo astronauts to reach the Moon in 1969.
C) is the accepted theory for the formation of the asteroid belt.
D) changes the speed and direction of a spacecraft nearing a massive planet.
E) explains how the solar system was formed after a near collision with another star.
Chapter 7: Earth
1. From the center outward, the correct order is:
A) liquid iron inner core, solid nickel outer core, rocky mantle, silicate crust.
B) solid metallic inner core, molten metal outer core, silicate mantle and crust.
C) solid metal core, molten metal hydrosphere, rocky lithosphere, gases in atmosphere.
D) solid rock core, liquid metal mantle, solid rock crust.
E) molten metal hydrosphere, molten rock lithosphere, solid silicate crust.
2. The oldest rocks on our crust are radioactively dated at about:
A) 200 million years old.
B) one billion years old.
C) 2.7 billion years old.
D) four billion years old.
E) 4.6 billion years old.
3. Which statement about the Earth's core is FALSE?
A) Its primary components are iron and nickel.
B) It generates a strong, stable magnetic field.
C) The pressure solidifies the center, but the outer core is fluid.
D) Its rotation gives rise to the Dynamo Effect.
E) It is about the same temperature as the photosphere of the Sun.
4. The region around Earth where the magnetic field traps charged particles is the:
A) ozone layer.
C) Van Allen Radiation Belts.
E) aurora borealis and aurstralis.
5. The presence of a magnetic field is a good indication that:
A) the Earth's interior is similar to Mercury's, as both have fields.
B) a huge iron meteorite lies somewhere high up in the mantle, not in the core.
C) we have a liquid metal outer core, spinning rapidly as we rotate.
D) the Earth's interior must be completely molten to the center.
E) the Earth's interior has had time to solidify, with a rigid bar magnet created.
6. Which body has the greatest gravitational pull on Earth?
A) the Sun
B) the Moon
E) None have an impact, as all are too distant.
Chapter 8: Moon and Mercury
1) The best way to find the exact distance to the Moon is to:
A) measure its exact size in the telescope.
B) use radar reflection times, about 2.56 second.
C) bounce lasers off the retroreflectors left on the surface by the Apollo landings.
D) make parallax measurements from observatories on opposite sides of the Earth.
E) use stellar occultations for precise timings of the moon's position.
2. Which planet shows us the widest range of temperatures between night and day?
3. How do the escape velocities of the jovians compare with the terrestrials?
A) Denser terrestrials all have higher escape velocities.
B) All planets have similar escape velocities.
C) The velocities vary greatly from planet to planet, with no general trend.
D) The more massive jovians all have higher escape velocities.
E) Escape velocity has no meaning if there is no solid surface.
4. Mercury experiences extreme high and low temperatures between night and day because:
A) it is so close to the Sun.
B) its dense atmosphere creates a runaway greenhouse.
C) its oceans are much hotter than ours.
D) Mercury has no axial tilt, with its equator always exposed to direct sunlight.
E) it has no atmosphere to moderate temperatures over the globe.
5. In size, Mercury is intermediate between:
A) Earth and Venus.
B) Mars and Earth.
C) the Moon and Mars.
D) Pluto and the Moon.
E) Ceres and Pluto.
6. The chief erosive agent now on the Moon is:
A) lunar ice melting and refreezing in the polar regions.
B) lava flows welling up in the mare.
C) volcanic vents in the rugged highlands.
D) the rain of micrometeorites chewing up the regolith.
E) rain from cometary debris melting as it enters the moon's atmosphere.
7. Which theory of the Moon's origin is now most in favor?
A) Like the moons of Jupiter, our moon condensed of leftovers around the equator of the newly formed Earth.
B) The rapidly spinning Earth slung the Moon off from what is now the Pacific Ocean basin.
C) The Moon formed as a separate planet, then was later captured by the Earth's gravity.
D) The Moon was a large comet, from the Oort Cloud, which has now lost almost all of its ices.
E) A Mars-size body struck the young Earth, tilting us over 23.5 degrees and blowing out ejecta that condensed into the Moon.
8. Which of these would support the capture theory of the Moon's origin?
A) the Caloris basin on Mercury
B) the retrograde orbit and large orbital inclination of Neptune's moon Triton
C) the rings of all the jovians lying around their equators
D) the Pluto-Charon system
E) the four large moons of Jupiter orbit its equator
Chapter 9: Venus
1) Why does Venus appear so bright to the eye?
A) It gets closer to us than any other planet does.
B) Venus lies closer to the Sun, so gets more intense sunlight.
C) The planet's cloud-cover is highly reflective, reflecting 60% of the sun's light.
D) As seen from Earth, the disk of Venus can appear larger than any other planet's.
E) All of the above are correct.
2. Earth and Venus are often called sister planets; in which ways are they most alike?
A) atmospheric composition and density
B) size, density, and surface gravity
C) surface temperature and pressure
D) cloud composition and meteorology
E) polar caps and rusty red deserts
3. The absence of a magnetic field on Venus probably stems from its:
A) nearness to the Sun.
B) extremely thick atmosphere.
C) slow rotation.
D) high surface temperatures
E) lower density than Earth, suggesting an absence of an iron core.
4. Which of the following contributes to Venus being so hot?
A) It is closer than Earth to the Sun.
B) Its atmosphere is much denser than the Earth's.
C) Its atmosphere is made chiefly of carbon dioxide.
D) It has very little axial tilt so the equator is always directly exposed to the Sun.
E) All of the above are factors.
Chapter 10: Mars
1) Why are Mars' seasons more extreme than ours?
A) Mars' orbit is more eccentric than the Earth's.
B) Mars' axial tilt is slightly greater than ours.
C) The major component of Mars' atmosphere can change phase seasonally.
D) Mars' atmosphere is thinner, with fewer greenhouse gases.
E) All of the above are true.
2. Which is the correct size order, from smallest to largest?
A) Mercury, Venus, Mars
B) The Moon, Earth, Mars
C) Mercury, Mars, Venus
D) Mercury, the Moon, Mars
E) Venus, Mars, Earth
3. Venus and Mars probably evolved differently from Earth because:
A) they are slightly bigger than Earth.
B) they are more massive than Earth.
C) they have thicker atmospheres than the Earth.
D) they formed sooner than Earth.
E) they orbit at different distances from the Sun.
4. Why is Mars red?
A) Dust storms on the planet have blasted the planet so fiercely that the rocks have reddened.
B) The iron in the surface rocks have been oxidized over time.
C) Mercuric oxide is abundant and has a red tint.
D) Sulfuric acid rain etched a reddish color into iron-rich surface rocks.
E) The ancient volcanoes poured out vast plains of molten sulfur, much as on Io, which has now solidified and preserved the reddish color.
5. The most striking valley in the solar system is:
A) the Grand Canyon in Arizona.
B) Gwenivere on Venus.
C) the Discovery Scarp of Mercury.
D) Valles Marineris on Mars.
E) Valhalla on Callisto.
6. Rank these magnetic fields, from weakest to strongest.
A) Venus, Mars, Mercury, Earth
B) Mars, Mercury, Venus, Earth
C) Earth, Venus, Mars, Mercury
D) The Moon, Mercury, Mars, Venus
E) Mars, Venus, Earth, Mercury
Chapter 11: Jupiter
1. How does the mass of Jupiter compare with that of the other planets?
A) It is slightly larger and more massive than Saturn.
B) It is similar to that of the Earth and Venus.
C) It is twice as massive as all other planets combined.
D) It is almost as massive as Saturn.
E) It is about a tenth the mass of the Sun.
2. How does the density of Jupiter compare to the terrestrials?
A) It is denser than all the terrestrials combined.
B) It is denser than the Moon, but less dense than any of the others.
C) Its density is slightly less than Mercury, but more than Mars.
D) Its density is about the same as Mars.
E) Its density is less than any terrestrial, but almost the same as the Sun's.
3. What is the name used to describe the dark bands encircling Jupiter?
B) brown stripes
D) zonal flows
E) convection cells
4. The most striking "cloudmark" in Jupiter's atmosphere is the:
A) Great Dark Spot.
B) Cassini Division.
C) Great Red Spot.
D) Black Hole.
E) Brown Dwarf.
5. What would Jupiter have needed to have become a star?
A) more moons
B) more mass
C) a slower rotation, like the Sun
D) a different chemical composition
E) a higher density
6. What is thought to lie at the center of Jupiter?
A) a core of liquid metallic hydrogen
B) a rocky core, not unlike a terrestrial planet
C) liquid helium under great pressure
D) a hydrosphere larger than Earth
E) hydrogen fusing into helium
7. How large is Jupiter's magnetosphere?
A) It is about as large as the Earth's.
B) It is so large it extends out to the orbit of Io.
C) It is a million times the volume of the Earth's, extending beyond the orbit of Saturn.
D) It extends inward to the orbit of Mars.
E) It envelopes even the Sun and rest of the solar system.
8. Which of the Galilean moons is the densest and most geologically active?
9. Which of the jovian moons is the largest and also the largest moon in the solar system, even bigger than Mercury?
Chapter 12: Saturn
1. A critical difference between Jupiter and Saturn is that:
A) Jupiter is much larger in diameter.
B) only Jupiter has belts and zones.
C) only Saturn has rings.
D) Jupiter is three times more massive.
E) only Jupiter is large enough to make liquid metallic hydrogen.
2. What are Saturn's rings?
A) a great disk of liquid helium
B) large rocky boulders moving in orbit around Saturn
C) a glowing, flat magnetospheric auroral display
D) a solid thin disc of material encircling Saturn
E) small icy particles moving in orbit around Saturn
3. Why are Saturn's rings so noticeable?
A) They are made of metallic hydrogen.
B) They are made of lots of fresh, bright icy particles from a recent breakup.
C) The particles in the rings are highly polished from numerous collisions with other particles.
D) They are made of nitrogen frost, like the bright surface of Triton.
E) Saturn is so bright, the rings reflect a lot of light from both Saturn and the Sun.
4. Titan is an interesting moon because:
A) beneath its clouds, Titan may be Earth-like, with liquid water.
B) the Huygens rover has sent back images of sedimentary rocks there.
C) it has a rich atmosphere that may resemble that of the early Earth.
D) it is known to have ice volcanism on its surface.
E) all of the above
Chapter 14: Solar System Debris
1. The orbits of most asteroids:
A) lie beyond Neptune.
B) lie entirely beyond the orbit of Mars.
C) cross the orbit of Mars.
D) cross the orbit of Earth.
E) cross the orbits of all four terrestrial planets.
2. What is the typical size of most known asteroids?
A) a few meters
B) a few kilometers
C) a few hundred kilometers
D) larger than the Moon
E) larger than the Earth
3. The nucleus, or main solid body, of a comet has a typical size of:
A) a few centimeters.
B) a few meters.
C) a few kilometers.
D) a few hundred kilometers.
E) a few thousand kilometers.
4. The orbits of most comets:
A) are like the planets, fairly circular and in the ecliptic plane.
B) lie almost entirely beyond the orbit of Neptune.
C) have perihelions within the orbits of Mercury.
D) go no farther out than Pluto, then return to the sun again.
E) are shorter than the 76 year period for Comet Halley.
5. The Oort Cloud is thought to be:
A) the cloud of gas and dust from which our solar system formed.
B) a cloud of debris that occasionally encounters the Earth, causing a meteor shower.
C) the spherical cloud of comets and some larger icy bodies surrounding the outer solar system.
D) a cloud of asteroids moving between the orbits of Mars and Jupiter.
E) the material in the ecliptic plane that creates the zodiacal light.
6. What are comets made of?
A) silicates and rocky dust
B) metallic dust particles
C) dark colored complex hydrocarbons
D) methane, ammonia, and water ice
E) all of the above
7. From its orbit, we now recognize Pluto as the largest member of the:
A) moons of Neptune.
B) asteroid belt.
C) Kuiper Belt.
D) Oort Cloud.
E) Zodiacal Belt.
8. Meteorites are valuable to astronomers because:
A) they may provide evidence about the process in which the solar system was born.
B) originated in other solar systems.
C) they contain diamonds and gold.
D) they reveal the contents of interstellar space.
E) they prove that life can only exist on the Earth.
9. What causes a meteor shower?
A) The solar wind chills the plasma and causes it to condense into particles.
B) Earth intercepts a stray swarm of asteroids left by a collision.
C) Earth crosses the orbit of an old comet, whose orbit is littered with debris.
D) Earth encounters the asteroid belt when Mars' gravity pushes it toward us.
E) A small constellation of dying stars disintegrates.
Chapter 17: Red Giants and Whiter Dwarfs
1. The Hertzsprung-Russell Diagram plots ________ against the spectral type or temperature.
B) luminosity or absolute magnitude
C) brightness or apparent magnitude
D) size or density
Chapter 25 Galaxies and Dark Matter
1. Based on galactic rotation curves and cluster dynamics, we think dark matter:
A) does not exist.
B) is a very minor component on the total mass of the universe.
C) is best detected by X-rays in intracluster gas clouds.
D) comprises about 90% of the entire mass of the universe.
E) exists, but has no observable effect on the visible universe.
2. Collisions between galaxies can:
A) turn irregulars into ellipticals.
B) cause both galaxies to collapse into a supermassive black hole.
C) cause bursts of star formation as starburst galaxies.
D) cause large numbers of stars to collide and explode.
E) hardly ever occur; like stars, galaxies are far apart, compared to their sizes.
3. The redshift of galaxies in the universe is correctly interpreted as:
A) a Doppler shift due to the motions of the galaxies through space.
B) an "aging" of the light.
C) the effect of intergalactic dust.
D) space itself is expanding with time; the wavelengths of photon are stretched while they travel through space.
E) the difference in temperatures of distant and nearby galaxies.
4. If the density of the universe is less than critical, then:
A) the universe will "survive" to expand forever.
B) the universe on average must be less than 2.73K in temperature.
C) the universal expansion must stop within about twenty billion years.
D) the universe must be static, and the red shifts are not cosmological.
E) the universe will begin contracting immediately into the "Big Crunch."
5. In which of the following models will the universe stop expanding?
A) High Density Universe
B) Low Density Universe
C) Steady State Universe
D) Critical Density Universe
E) Euclidean Universe
6. What is the meaning of a "closed" universe?
A) The universe will expand forever.
B) The universe will someday stop expanding and start to collapse.
C) The universe will stop expanding in an infinite amount of time.
D) The universe is in a steady-state.
E) The universe will disappear into a white hole in time.
7. The cosmic microwave background is important mostly because:
A) its detection lead to the discovery of dark energy.
B) its detection opened a new form of radiation to observation.
C) it confirmed a major prediction made by the Big Bang theory.
D) it showed that the universe is open.
E) it showed that the universe is closed.