Astronomy Test 1, 2, and 3 MCQ's and Answers

What sort of system can produce a supernova that completely destroys one of the stars? A) White dwarf plus black hole B) White dwarf plus giant star C) White dwarf plus neutron star D) Black hole plus giant star E) Neutron star plus giant star

B

Which of the following is not true of a typical globular cluster of stars? A) It contains thousands of or up to a million stars B) The stars are usually quite young C) It would probably contain lots of white dwarfs and red giant stars D) They are usually found in the halo of a galaxy, not the disk E) Actually, these are all generally properties of globular clusters

B

Which of the following is true about volcanism on Mercury? A) There is no evidence that there were ever volcanoes on Mercury B) There is strong evidence that there were volcanoes in the distant past, but probably not any more C) There are probably still active volcanoes on Mercury, though we have never seen one D) Active volcanoes have been identified, but they are no more common than they are on Earth E) Active volcanoes have been seen and are much more common than on Earth

B

Which of the following observations helped ancient astronomers figure out the shape of the earth? A. a solar eclipse B. a lunar eclipse C. a terrestrial eclipse D. the angle of the moon at first or third quarter E. None of the above, ancient astronomers were unable to deduce the shape of the Earth

B

Which outer layer of the Sun has the highest temperature? A) Photosphere B) Corona C) Chromosphere D) Exosphere E) Thermosphere

B

Which two factors make a planet or moon more likely to keep its atmosphere? A) Being close to the Sun and having a high mass B) Being far from the Sun and having a high mass C) Being close to the Sun and having a low mass D) Being far from the Sun and having a low mass E) Paying your dues to the Atmosphere Protection Fairies Union

B

A massive star supernova is most likely to occur in a region where A) All the stars are very luminous B) All the stars are very dim C) There are a lot of new stars being born D) All the stars are very old E) None of the above

C

According to Kepler's second law of planetary motion, a planet, as it orbits the Sun A) Moves equal angles in equal time B) Moves an equal distance in equal times C) Sweeps out equal areas in equal times D) Moves the same distance as any other planet in the same time E) None of the above

C

As viewed from here in the northern hemisphere, do the stars rise and set over the course of the day, just as the sun does? A. Yes, they all do B. yes, except for some near the equator called ecliptic stars C. yes, except for some in the north called circumpolar stars D. yes, except for some in the east and west called morning and evening stars E. no, the stars are stationary as viewed from Earth

C

How does the gravitational force of Jupiter (a massive planet) on Europa (a small moon) compare to the pull of Europa's force on Jupiter? A) Jupiter's force is stronger B) Europa's force is stronger C) They are exactly the same D) There is insufficient information to determine the answer E) I have no idea; please mark this one wrong

C

Sometimes, solar eclipses are annular eclipses, where the rim of the Sun is just visible around the edges of the Moon, as sketeched at right. What circumstance allows this to happen sometimes? A) The Sun is larger in size than usual B) The Sun is smaller in size than usual C) The Moon is farther away than usual D) The Moon is closer than usual E) The Moon is moving more quickly than usual

C

Suppose the electrons in a thin gas of atoms were put into high energy states. What sort of light would be produced from such an atom? A) A continuous spectrum, with light of all frequencies B) A dark-line spectrum, with almost all frequencies, but a few missing C) A bright-line spectrum, with only a few frequencies present D) A white noise spectrum, with the brightness for every frequency proportional to 1/f E) No light; an isolated atom can't produce light

C

The gas giants are much more massive than the terrestrial planets because A) They are made of a higher percentage of rock B) They are made of a higher percentage of metal C) In addition to rock and metal, they have thick layers of ices and thick atmospheres D) They have large quantities of dense materials like uranium and osmium, which are rare on the terrestrial planets E) They formed in the thicker part of the protoplanetary nebula, so they have more of everything

C

The initial cloud of gas from which stars and planets form is called a A) Protoplanetary disk B) Accretion disk C) Molecular cloud D) H-I region E) Reflection nebula

C

The purpose of a spectrometer is to A) Combine all the light from a source into a single beam and measure the total power of the spectrum B) Take an image of a large range of space all at once C) Divide light into its component wavelengths/frequencies D) Filter out background light E) Compensate for atmospheric turbulence

C

What event is responsible for the ultimate death of the Sun? A) All the hydrogen runs out B) All the helium runs out C) The outer layers of the Sun are blown away by strong winds D) The Sun burns all the way to iron, which cannot burn any more E) The core of the Sun collapses under its immense gravity

C

What happens to a star during the white dwarf stage? A) It gradually gets cooler and shrinks B) It gradually gets cooler and grows C) It gradually gets cooler and stays the same size D) It gradually gets hotter and grows E) It gradually gets hooter and shrinks

C

What is the ultimate source of heat that keeps the interior of the Earth hot? A) Light from the Sun B) The Solar wind C) Radioactive decay of elements like uranium and thorium inside the Earth D) Heat of formation left over from when the Earth formed E) Tidal heating caused by the gravitational influence of the Sun

C

What would be the best method for estimating the age of a cluster of stars? A) Measure the fraction of helium in the spectrum of a typical star B) Measure the relative fraction of main sequence stars to dead stars, such as white dwarfs C) Make a Hertzsprung-Russell diagram for the cluster, and see where it "turns off" from the main sequence D) Measure the velocity of the stars and see how much the cluster has spread over time E) Measure the mass of the most massive star that is still living in the cluster

C

Which force is it that keeps electrons bound in atoms? A) (Strong) nuclear B) Weak nuclear C) Electromagnetic D) Gravity E) Higgs field

C

Which of the following is largest in diameter? A) Titan B) Mercury C) Ganymede D) Triton E) Pluto

C

Which of the following is the primary way that we know what the Sun is made of? A) The overall color of the Sun B) Sample return missions that have dived into the corona of the Sun C) The wavelengths of the dark lines in the spectrum of the Sun D) The measurement of the rates of fusion in the Sun E) Stellar models that balance the pressure versus gravity for the Sun

C

Which of the following would, by itself, indicate that a star is a nearby star? A) The star is bright; easily seen by the naked eye B) The star is an O star and yet difficult to detect C) The star seems to wobble back and forth every year by a large amount compared to background stars D) The star seems to wobble back and forth every year by a small amount compared to background stars E) None of the above

C

Which of the terrestrial planets has the densest atmosphere? A) Earth B) Mars C) Venus D) Mercury E) None of these

C

Which particles are found in the nucleus of an atom? A) Protons (only) B) Neutrons (only) C) Protons and neutrons, but not electrons D) Protons, neutrons, and electrons, but not neutrinos E) Protons, neutrons, electrons, and neutrinos

C

Which source gives us samples that we can use to determine the approximate age of the Solar system? A) Stony meteorites B) Iron meteorites C) Carbon-rich primitive meteorites D) Apollo moon rocks E) Mars Sample Return Mission

C

Besides visible light, what other type of astronomy can be done from the surface of the Earth? A) Infrared B) Ultraviolet C) X-rays D) Radio E) Gamma rays

D

Copernicus' main contribution to understanding the motions of the planets was A. he argued that you have to use ellipses, not circles, to describe the motions of planets B. He argued that the motion was due to the universal law of gravitation C. he invented calculus, which was necessary to solve the equations D. he argued that the sun was the center of the solar system, not earth E. he discovered that venus had phases

D

How does the position of the Sun principally differ at noon in the summer compared to the winter? A) It is farther east in the summer and farther west in the winter B) It is farther west in the summer and farther east in the winter C) It is lower in the sky in the summer and higher in the winter D) It is higher in the sky in the summer and lower in the winter E) None of the above

D

In what way does the life history of a two solar mass star differ from a one solar mass star? A) The two solar mass star ends its life as a neutron star A B C D E B) The two solar mass star ends its life as a black hole C) The two solar mass star eventually burns carbon and oxygen to heavier elements D) The two solar mass star does the same thing as a one solar mass star, but does it faster E) The two solar mass star does the same thing as a one solar mass star, but does it slower

D

In what way, according to the currently accepted definition, does a dwarf planet differ from a planet? A) A dwarf planet does not have an atmosphere; a planet does B) A dwarf planet need not be round (in hydrostatic equilibrium), but a planet must be C) A dwarf planet need not orbit a star; it can orbit another planet D) A dwarf planet need not have a lot more mass than all other objects in similar orbits E) A dwarf planet does not have a moon of its own; a planet does

D

Just before a high mass star starts to undergo a massive star supernova, the core is made primarily of A) Helium B) Carbon/Oxygen C) Silicon D) Iron E) Neon

D

The main component of the gas giant's atmospheres is/are: A) Nitrogen B) Carbon dioxide C) Helium and Xenon D) Hydrogen and helium E) Oxygen

D

What is the outer core of the Earth probably made of? A) Solid rock B) Liquid rock C) Solid metal D) Liquid metal E) None of these

D

What particles coming from the Sun confirm that it is currently undergoing nuclear fusion? A) Helium B) Photons C) Electrons D) Neutrinos E) Neutrons

D

What probably happened to Earth's first (primary) atmosphere? A) It underwent chemical reactions and is now mostly in our oceans B) It was subducted inside the Earth by the movement of tectonic plates C) It was converted by plants into oxygen D) It was demolished by winds coming from the Sun E) Nothing; we still have it

D

What sign would indicate that a particular star is moving away from us? A) If its overall color were slightly blueer than expected B) If its overall color were slightly redder than expected C) If its spectral lines are shifted towards the blue end of the spectrum D) If its spectral lines are shifted towards the red end of the spectrum E) If the luminosity were slightly less than expected

D

What would happen to the Moon if it came too close to the Earth, inside the Roche limit? A) It would immediately move back out to a larger distance, beyond the Roche limit B) It would be absorbed into the Earth due to the Earth's large gravity C) It would be broken in half by tidal forces, and that would be it D) It would be broken in half over and over, ending up as a lot of tiny moons E) It would be frozen in place, orbiting the Earth exactly once per day

D

Which object(s) cause significant (easily noticeable) effects on the tides of Earth? A) Sun (only) B) Moon (only) C) Planets (only) D) The Sun and Moon, but not the p

D

Which of the following does not convey approximately the same information as the rest? A) Color B) Surface temperature C) Spectral class D) Luminosity E) Actually, all of these do approximately correspond to each other

D

Which of the following observations seemed to indicate rather convincingly that the Sun, rather than the Earth, was the center of the Solar System? A) Sunspots on the Sun B) Mountains on the Moon C) Moons around Jupiter D) The phases of Venus E) Retrograde motion of the planets

D

Which of the gas giant planet rotates on an axis that is tipped way over compared to its orbit? A) Saturn B) Jupiter C) Neptune D) Uranus E) None of them

D

Which reason makes it useful to have a very large objective (first) mirror or lens? A) It allows you to see much wider objects B) It allows you to compensate for atmospheric turbulence C) It allows you to do astronomy with longer wavelengths D) It allows you to see dimmer objects E) It allows you to see around small intervening objects

D

Why does the edge of the Sun look less bright than when we look at the center of the Sun? A) The hottest part of the Sun is the part pointed towards us B) The fusion rate is fastest on the side of the Sun facing Earth C) When we look at the center of the Sun, we see not only the Sun's light, but also the reflection of the Earth shining back at us D) We see deeper into the layers of the Sun when we looks straight down, where the Sun is hotter E) The Sun is closer to the Earth at the central point, making it looks brighter

D

Why is it believed that the Moon has so little metal, in contrast to the Earth? A) It originally formed in a part of the nebula which had very little metal B) The Earth's greater gravity pulled all the metal to itself C) The Earth has a strong magnetic field, which pulled the metal in D) The Moon probably formed from a giant impact, so it is made mostly from the rocky mantle of the Earth E) The Moon cooled more quickly, being smaller, before it could accumulate any metal

D

3. The rings of Saturn are made of primarily ________ with a little bit of ________ mixed in A) Ice, dust B) Dust, ice C) Ice, gas D) Gas, ice E) Gas, dust

A

A white dwarf with the same mass as the Sun is about the size of A) The Earth B) The Sun C) Jupiter D) A city E) A pinhead

A

Does the moon rotate as it goes around the Earth? A. Yes, at the same rate it goes around the Earth B. Yes, and faster than it is going around the Earth C. yes, and slower than it is going around the Earth D. yes, and backwards compared to how it orbits the Earth E. No

A

How does the Sun rotate? A) The equator goes around in less time than the rest, but in the same direction B) The equator goes around in more time than the rest, but in the same direction C) The entire Sun rotates at the same rate, like a solid object D) The equator goes around one direction while the rest goes around the opposite direction E) It is impossible to know, since the Sun has no surface features that can be used to measure rotation

A

How does the number of sunspots change over time? A) It rises and falls in an approximate eleven year cycle B) It rises and falls about every month at the rate the Sun rotates C) It has been steadily increasing over time D) It has been steadily decreasing over time E) It is on the average steady from month to month and year to year

A

If I have two atoms that are both sodium atoms, what is guaranteed to be the same about both of them? A) The charge of their nuclei B) The number of electrons C) Their mass D) Their chemical bonds E) The number of neutrons

A

Suppose we know the brightness of a star. What additional information would allow us to determine the distance to the star? A) Luminosity B) Temperature C) Radius D) Mass E) Color

A

The first astronomer who was able to extensively use a telescope was A) Galileo B) Kepler C) Newton D) Tycho Brahe E) Copernicus

A

The hottest stars in the HR diagram can be found in what part of the diagram? A) Left B) Right C) Top D) Bottom E) Middle

A

The largest known mountain in the Solar system is on _____ and the largest valley is on ______. A) Mars, Mars B) Mars, Venus C) Mars, Earth D) Earth, Mars E) Earth, Venus

A

To form planets, first you have tiny pieces come together due to _________ to form planetismals, and then the planetismals come together due to ___________ . A) Random collisions, gravity B) Gravity, random collisions C) Magnetic forces, gravity D) Gravity, magnetic forces E) Magnetic forces, random collisions

A

Which is the largest moon of all the terrestrial planets? A) Earth's Moon B) Ganymede C) Phobos D) Deimos E) Titan

A

Which of the following best explains why it is hotter at the equator of the Earth than the poles? A) The Sun shines almost directly down on the equator, but it shines at an angle at the poles B) The Sun is closer to the equator than to the poles C) There are long periods of darkness and only very short days at the poles D) It is much cloudier at the poles than at the equator E) There is warm ocean water at the equator, which warms the climate

A

Which technique has actually succeeded in finding the largest number of exoplanets? A) Transit method, where you watch the star getting dimmer as the planet gets in front of it B) Pulsar timing; where you study the timing of precise pulses from the star C) Radial velocity method, where you study the Doppler shift of the star D) Direct imaging, where you search of the faint image of a planet next to a star E) Astrometry, where you watch the star wobble back and forth due to the planet's gravity

A

Why do planets normally have a layered appearance, with metal, then rock, then ices (if any) and then their atmospheres? A) Gravity: the heaviest components sank to the bottom B) Magnetism: Metals are the most magnetic and fall first C) Temperature: Metals condense at the highest temperatures, so they formed first, etc. D) Layered formation: The metals entered the solar system first and formed the cores, then came the rocks, etc. E) Radioactivity: The materials with the highest radioactivity naturally go to the center

A

Why is it that eclipses occur roughly only two months out of the year, rather than much more spread out through the year? A) The tilt of the Moon's orbit around Earth guarantees that the Sun-Moon-Earth system can only line up at certain times of the year B) It takes about six months for the Moon to go around the Earth, which is required for a new eclipse C) During most months, the Moon is so far away that an eclipse would not be noticeable D) During the other months, the eclipse happens on the far side of the Moon, which we cannot see E) The Earth moves in a way that is synchronized with the Moon's motion, so that they never line up except during these months

A

Why is the helium burning stage of a star so much shorter than the hydrogen burning stage? A) Because the star is more luminous and the burning produces less energy per fusion B) Because the star is less luminous and the burning produces less energy per fusion C) Because the star is more luminous and the burning produces more energy per fusion D) Because the star is less luminous and the burning produces more energy per fusion E) None of the above

A

Astronomers often like to do radio astronomy using widely separated radio telescopes. The advantage of this is that A) If one is blocked by clouds, the other might not be B) The images from the two can be combined (interfered) in such a way as to give a much more detailed image C) One can check to make sure it is not just noise from a local source D) One can read the radio waves while the other sends a signal back E) Since designing a radio telescope is most of the expense, you can design once and build twice

B

For a low mass star like the Sun, what is going on in the center of the star when it reaches its largest stage? A) It consists of inert helium B) It consists of inert carbon and oxygen C) It has hydrogen burning to helium D) It has helium burning to carbon and oxygen E) It has carbon and oxygen burning to heavier elements

B

For which planet, and why, do visible light pictures from space not tell us about the surface? A) Mars, because it is covered by polar caps that hide the surface B) Venus, because it is covered by clouds all the time C) Venus, because it is uniform in color and you can't see anything D) Mercury, because without an atmosphere, there is nothing to see E) Mercury, because it is so close to the Sun it is too bright to take pictures of

B

If a star is a main sequence star of spectral class B2, then we can conclude that it is probably also A) A low mass star B) A high mass star C) A non-luminous star D) An old star E) A star in a binary system

B

If an object is moving towards us, its light will be: A) Blue-shifted, which means shifted to longer wavelengths B) Blue-shifted, which means shifted to shorter wavelengths C) Red-shifted, which means shifted to longer wavelengths D) Red-shifted, which means shifted to shorter wavelengths E) None of the above

B

If two stars are separated by a distance of 3 AU, and orbit each other once every 6 years, what must be the combined mass of the two stars, in solar masses? A) 0.0417 MSun B) 0.75 MSun C) 1.33 MSun D) 2.25 MSun E) 24 MSun

B

In order from most to least common, what is the nebula from which stars and planets form made of? A) Hydrogen and helium, metal and rock, ices B) Hydrogen and helium, ices, metal and rock C) Ices, hydrogen and helium, metal and rock D) Ices, metal and rock, hydrogen and helium E) Metal and rock, ices, hydrogen and helium

B

In the old TV show Star Trek, when the engines of the Enterprise failed, the ship would stop orbiting and begin slowly spiraling towards whatever planet they were orbiting. What's wrong with this idea? A) If the engines failed, the ship should fall immediately into the planet B) If the engines failed, the ship should continue following whatever orbit it was on before: an ellipse, parabola, or hyperbola C) If the engines failed, the ship should move in a straight line whichever direction it was going before D) If the engines failed, the ship should immediately halt wherever it is E) Nothing; this is in fact exactly what should happen

B

Short period comets probably originate in which location? A) Oort Cloud B) Kuiper belt C) Asteroid belt D) Neptune's moons E) The Sun

B

The amount of time from new moon to first quarter would probably be best approximated as A) 1 day B) 1 week C) 2 weeks D) 1 month E) 1 year

B

The coldest temperature possible is A) -273 K B) 0 K C) 3 K D) 300 K E) 5800 K

B

The spectrum from a planetary nebula is a A) Dark line spectrum B) Bright line spectrum C) Continuous spectrum D) Bright line spectrum for low mass stars; dark line spectrum for high mass stars E) Dark line spectrum for low mass stars; bright line spectrum for high mass stars

B

What fundamental property makes a plasma different from an ordinary gas? A) It is made primarily of hydrogen rather than some other gas B) It is so hot that the electrons have become detached from the atoms C) It is hot enough for nuclear fusion to occur D) It is hot enough that it glows in visible light E) It has magnetic fields

B

Compared to the stars, how do the planets move? A) No, they are stationary B) Yes, they always move west to east C) Yes, they always move east to west D) Yes, they sometimes move north to south and sometimes south to north E) Yes, they sometimes move west to east and sometimes east to west

E

Heat is transported out of the Sun by A) Convection throughout the Sun B) Radiation throughout the Sun C) Conduction throughout the Sun D) Radiation in the outer layers of the Sun, and convection in the interior E) Convection on the outer layers of the Sun, and radiation in the interior

E

If we wanted to cut the pressure of an ideal gas in half, which of the following would work? A) Double the mass of the particles B) Double the temperature C) Double the number density D) Cut the mass of the particles in half E) Cut the temperature in half

E

In addition to Saturn, what other planets have rings around them? A) Uranus (only) B) Neptune (only) C) Jupiter (only) D) Uranus and Neptune, but not Jupiter E) Uranus, Neptune, and Jupiter

E

In which of the following stages does hydrogen burning occur anywhere in a star? A) Double shell burning (only) B) Protostar (only) C) Main sequence (only) D) White dwarf (only) E) Main sequence and double shell burning

E

In which phase(s) of the Moon listed below would the sun and moon combine to cause especially large tides (spring tide) A. New moon (only) B. First quarter (only) C. Full moon (only) D. New moon and first quarter, but not full moon E. new moon and full moon, but not first quarter

E

Pulsars probably have at their heart what sort of star? A) Red giant B) White dwarf C) Black hole D) Planetary nebula E) Neutron star

E

Suppose a star was 4 times the surface temperature of the Sun, but had the same radius. How many times more luminous than the Sun would it be? A) 2 B) 4 C) 16 D) 64 E) 256

E

The Earth contains an enormous number of positively charged nuclei. Why does this not cause the entire Earth to expand and explode from electric forces? A. the electromagnetic force between two nuclei is attractive, not repulsive B. The gravitational force is much stronger, and overcomes this force C. the earth is exploding, very slowly, and this is part of the universal expansion of the Universe D. Nuclei also have magnetic forces, which hold them together E. the positive charge of the nuclei is cancelled by negative charges from the electrons

E

The disk from which the planets formed often is spinning fairly fast. How did it get such a fast spin? A) Magnetic fields from the rotating star accelerate the disk to high speeds B) Passing stars tend to pull on it, always spinning it faster and faster C) Early stellar winds spin it up to high speed D) Gas expelled by this disk always pushes backwards, accelerating it E) The disk shrank at first, and as it shrank, slow spin gets converted into fast spin

E

What is the second most common element in a typical star, such as the Sun? A) Carbon B) Iron C) Oxygen D) Hydrogen E) Helium

E

Which moon has active volcanoes that are spewing sulfur? A) Europa B) Enceladus C) Triton D) Titan E) Io

E

Which of the following can not be deduced simply by observing the phases of the Moon? A) The Moon goes around the Earth B) The Moon is illuminated by the Sun C) The Moon is a sphere, not a flat disk D) The Moon is much closer than the Sun E) The Moon is much less massive than the Sun

E

Which of the following events is believed can cause intense bursts of gamma rays? [1] Collapse of very high mass star [2] Merger of two white dwarfs [3] Merger of two neutron stars A) [1] only B) [2] only C) [3] only D) [1] and [2] E) [1] and [3]

E

Which of the following has the most energy for a single photon? A) Visible B) Infrared C) Radio D) Microwaves E) X-rays

E

Which of the following would reduce the gravitational force between the Earth and the Moon by a factor of four? A) Doubling the mass of the Earth B) Halving the mass of the Earth C) Doubling the mass of the Moon D) Halving the mass of the Moon E) Doubling the distance between the Earth and Moon

E

Which of the letters at right corresponds roughly to where one would find a red giant star on the Hertzsprung-Russell diagram?

E

Which planet has a large moon that orbits backwards compared to the direction of rotation of the planet? A) Saturn B) Jupiter C) Earth D) Uranus E) Neptune

E

Why are earthquakes so useful in helping us learn about what the Earth is like on the inside? A) Earthquakes bring us samples from the interior B) Earthquakes are responding to motions in the core of the Earth, so indirectly they tell us about the core this way C) Earthquakes temporarily shift dense parts of the Earth out of the way, so we can use radar to detect the interior D) Earthquakes create cracks so we can send in robotic probes to study the interior E) Earthquakes cause vibrations to pass through the entire Earth, and since different materials respond different ways, we can learn what the Earth is probably made of

E