module 5

An astronomy textbook, when printed out, weighs four pounds on the surface of the Earth. After finishing your course, you are so tired of the book, you arrange for NASA to shoot it into space. When it is twice as far from the center of the Earth than when you were reading it, what would it weigh? (Note, assume that the book has been moving away from the Earth, not falling freely around it.

1 lb

If a star is 20 parsecs away, its parallax must be:

1/20th of an arcsecond

When England and the American colonies finally adopted the Gregorian calendar in 1752, what dramatic change had to be made?

12 days had to be dropped to bring the date and the seasons back into accord

A star is 230 light years away. The light we see tonight from that star left it

230 years ago

The half-life of a radioactive element is the time it takes for half the sample to decay; we determine how many half-lives have passed by how much of a sample remains the radioactive element and how much has become the decay product. In this way, we have estimated the age of the Moon and Earth to be roughly ________ year.

4.5 billion

The first ordinary star (other than our own Sun) around which planets were definitely discovered was:

51 Pegasi

The Sun, a star that is brighter than about 80% of the stars in the Galaxy, is by far the most massive member of the solar system. What percentage of the total mass in the solar system does the Sun contain?

99.8%

Which of the following statements about a Type II Supernova is true?

A Type II supernova occurs at the end of the life of a star with 10 times the mass of our Sun or more

The astronomer who, at the turn of the century, measured the spectra of hundreds of thousands of stars, leaving a catalog that astronomers used for the rest of the century, was:

Annie Cannon

Which ancient Greek thinker suggested (long before Copernicus) that the Earth is moving around the Sun?

Aristarchus

When the authors of our textbook say that astronomers are like police detectives trying to solve crimes, they are explaining that:

Both astronomers and detectives must test their hypotheses against any evidence that they gather

An astronomy class is so excited by the discovery of planets around other stars that they decide to do a library exhibit on the subject so that everyone in the school can learn about it. In this exhibit they want to pay tribute to both the astronomers of today who have done the work And some of the scientists of the past whose work was essential to making the discoveries possible (and directly related to the techniques involved). Which of the following scientists of the past should definitely be included in the exhibit?

Christian Doppler

In Copernicus' day, people were worried about the idea that the celestial sphere seemed to turn around us once a day because the Earth rotates. They argued that if the Earth were to rotate so fast, it should fly apart. According to our textbook, what was one response Copernicus had to this worry?

Copernicus argued that the idea that the much larger celestial sphere is turning once a day (and the Earth is not) meant that the celestial sphere would be torn apart even more]

When astronomers carefully examine the planets found by Kepler and draw conclusions from the Kepler sample, what do they conclude about planets the size of Earth

Earth-sized planets are common, but so are planets somewhat bigger than Earth

The four separate processes (volcanism, impact cratering, erosion and tectonics) listed below can also be interrelated, so although one may be most important to a particular feature, others often also play a role. For example, some erosion has occurred on the volcanic island of Hawaii, there are impact craters on the slopes of Olympus Mons, and volcanism and tectonics almost always go hand-in-hand. The Earth's Grand Canyon is an example of

Erosion

Our solar system has 8 planets orbiting the Sun. Based on the discoveries of exoplanets so far, what can we say about a star with 8 planets?

Even though planets were only discovered starting in 1995, so we can't yet find planets that take centuries to go around their star, we already know other stars with 8 planets and we are likely to find more

Pluto was discovered via its gravitational effect on Neptune.

False

The solid surface of Jupiter lies just below the cloud layers that are visible from Earth.

False

The scientist who made the first telescopic survey of the Milky Way and discovered that it is composed of a huge number of individual stars was

Galileo Galilei

In what fundamental way did the work of Galileo differ from his predecessors who had thought about the sky?

Galileo used instruments and experiments to show him what nature was doing, instead of relying on pure logic

The "prime meridian" (where longitude equals zero) passes through:

Greenwich, England

The period-luminosity relationship for Cepheid variables was discovered by

Henrietta Leavitt

Who was the astronomer who is the "H" in H-R diagram?

Hertzsprung

Jovian atmospheres are composed mainly of hydrogen and helium, with smaller amounts of methane, ammonia, water, and other chemicals. How does a jovian planet's chemical composition affect its storms?

It determines what color the storms are.

The Earth is closest to the Sun in which month of the year?

January

The scientist who formulated the three laws of planetary motion by analyzing the data on the precise location of planets in the sky was:

Johannes Kepler

When NASA and a group of astronomers sent up a spacecraft designed to find planets orbiting other stars, they named it after Kepler. Why was this an appropriate name?

Kepler figured out the rules of planetary motion, which planets in our solar system and planets elsewhere must obey

Assume that all the planets started out equally hot inside. Based on their expected cooling rates, which one cooled the fastest?

Mercury

The planet in our solar system with the shortest period of revolution is:

Mercury

Which of the following Mars surface features provides dramatic evidence that volcanism has played a role in shaping the surface of Mars?

Olympus Mons

Your weird cousin, who is really into astronomy, decides that the return address he uses on his letters is incomplete! To his city, state, and country, he begins to add: "North America, Earth, Solar System..." If he now wants to include the name of the Galaxy's spiral-structure feature in which the Earth is located, how should his address end?

Orion Spur

Which of the following correctly describes the motion of the particles in Saturn's rings?

Particles in the inner rings orbit Saturn at a faster speed than particles in the outer rings.

Which of the following are icy dwarf planets, that exist in an ice realm on the fringes of the main planetary system known as the Kuiper belt?

Pluto, Makemake, Haumea, and Eris

The star that is currently closest to the North Celestial Pole is:

Polaris

Which of the following stars is a Cepheid variable?

Polaris

What is the closest star to the Sun?

Proxima Centauri

The astrophysicist who first calculated the highest mass that a dying star can have and still be a white dwarf was

S. Chandrasekhar

Some college students in CA decide to form a secret society that would meet each year after graduation at a time when the day and night were the same length. Which of the following would be a time they could meet?

September 23

The first artificial satellite the human race lofted into orbit was called:

Sputnik

Assuming that features you see on Mars are similar to features found on Earth, what would a casual inspection of a photo of the Martin surface lead you to suspect about water on Mars?

Surface water only exists as frozen ice.

Some sensationalist reporters have called the totally eclipsed moon "the blood moon." Why does the Moon look reddish to us when there is a total lunar eclipse?

The Earth's atmosphere bends different colors of light to a different degree. During a total lunar eclipse, the red light of the Sun, filtering through the Earth's atmosphere colors the Moon red

Of these which is the closest to us?

The Moon

The natural object (not one that humans built) in space that's closest to Earth is

The Moon

The Earth's escape speed (the speed you need to get away forever) is about 25,000 miles per hour. Escape speed depends on the gravity of the object trying to hold the spacecraft from escaping. Based on your understanding of gravity, how will the escape speed from the Moon compare to the escape speed from Earth?

The Moon's escape speed will be smaller than Earth's

How does the Sun influence the tides that we experience on Earth?

The Sun also raises tides on Earth, but its effect is smaller than that of the Moon

Of these, which is the largest?

The Universe

Which of the following statements about the Sun's photosphere is NOT TRUE?

The photosphere is significantly hotter than all the layers of the Sun beneath it (further inward)

Which statement about the solar month and the sidereal month is correct?

The solar month is more than two days longer than the sidereal month

How does the tidal force change with distance?

The tidal force increases when distance decreases.

Which object in the solar system has a density most similar to Pluto's?

Triton, Neptune's largest moon

A very rich, very shady international banker (with residences all over the globe, including Los Angeles, CA) mysteriously disappears. Someone later mails a wide-angle photo of his body to a London newspaper, taken on June 22, showing the Sun exactly overhead at noon. What can the police deduce from this photograph about where on Earth the body is located?

Tropic of Cancer

A mass extinction is the sudden disappearance in the fossil record of a large number of species of life, to be replaced by fossils of new species in subsequent layers; mass extinctions are indicators of catastrophic changes in the environment, such as might be produced by a large impact on Earth.

True

During the northern summer of Uranus, an observer near the north pole would observe the Sun high and almost stationary in the sky.

True

Earth, like the Moon and other planets, has been influenced by the impacts of cosmic debris, including such recent examples as Meteor Crater and the Tunguska explosion.

True

Storms in the jovian planets' atmospheres are generally much longer lived than storms on Earth.

True

The ages of the surfaces of objects in the solar system can be estimated by counting craters: on a given world, a more heavily cratered region will generally be older than one that is less cratered.

True

Astronomers have observed storms on all of the jovian planets, but only three of them have large storms. On which of the jovian planets has a large storm never been observed?

Uranus

Where can you find the largest atmospheric pressure?

Venus

Which planet in the solar system rotates backwards (It's spin as seen from North is clockwise, rather than counter-clockwise like the rest)?

Venus

The first astronomer to show that spiral nebulae (today called spiral galaxies) have large Doppler shifts was

Vesto Slipher

Which of the following statements about dark matter in the Galaxy is False?

While the dark matter cannot be observed with our present-day instruments, we still have a pretty good idea what it consist of

The largest refracting telescope in the world, financed by a Chicago millionaire in the 1890's, is at the:

Yerkes Observatory

Astronomers today know a lot about the size and shape of the Milky Way Galaxy. Which of the following common objects most resembles the shape of our Galaxy?

a CD or DVD, or Blu Ray

An idealized object that does not reflect or scatter any radiation that hits it, but simply absorbs every bit of radiation that falls on it is called:

a blackbody

Some objects in space just don't have what it takes to be a star (just like many hopefuls in Hollywood don't.) Which of the following is a "failed star", an object with too little mass to qualify as a star?

a brown dwarf

About two thirds of the nearby spiral galaxies (which we can study in more detail) don't have a round central bulge, but instead show

a central bulge with a bar of stars in the middle

Objects orbiting around the center of the Milky Way obey Kepler's 3rd Law. This means that:

a cloud of gas or star that is further from the center will generally take more time to orbit

Which of the following has the greatest average energy of random atomic and molecular motion?

a cube of the Sun

Which of the following has the greatest density?

a cubic meter of lead

Oort proposed in 1950 that long-period comets are derived from what we now call the Oort cloud, which surrounds the Sun out to about 50,000 AU. Comets also come from the Kuiper belt, a disk-shaped region beyond the orbit of Neptune, extending to 50 AU from the Sun. Once a comet is diverted into the inner solar system, it typically survives no more than __________ perihelion passages before losing all its volatiles.

a few thousand

Olympus Mons is

a giant mountain on Mars, with a crater at its top.

A type of star cluster that contains mostly very old stars is

a globular star cluster

Which of the following correctly describes what is meant by a runaway greenhouse effect?

a greenhouse effect so extreme that if a planet has oceans, it makes the oceans boil away completely.

The Orion Nebula is

a large cloud of gas and dust illuminated by the light of newly formed stars within it

Who pays the bill for the energy generated by nuclear fusion in the Sun? In other words, where does the energy pouring out of the Sun come from ultimately?

a little bit of mass is lost in each fusion reaction and is turned into energy (the Sun is losing mass)

According to the formula E=mc2

a little mass can be converted into a substantial amount of energy

Valles Marineris is

a long system of canyons stretching nearly a fifth of the way around Mars

Which of the following particles has the lowest mass?

a neutrino

Where does the energy come from that allows the Crab Nebula to keep shining almost a 1000 years after the star exploded? (Who ultimately "pays the energy bill"?)

a neutron star is slowing down (losing rotation energy)

Astronomers making observations in our Galaxy have been able to rule out a number of suggestions for what the dark matter in the Galaxy might be. Which of the following have we Not been able to rule out (which suggestion is still "in the running")?

a new kind of subatomic particle

What happens as an electron falls from a higher level to a lower level in an atom?

a photon is given off

You suddenly get an uncontrollable urge to find out more about the other side of the Milky Way Galaxy (the regions beyond the center). Where should you rush off to?

a radio telescope that can observe at 21-cm wavelengths

In recent decades, astronomers discovered stars even cooler than the traditional spectral type M stars recently. Astronomers gave these cool stars a new spectral type, L. If you wanted to go out and find more such type L stars, what kind of instrument would it be smart to use?

a sensitive infra-red telescope

Physicists Kelvin and Helmholtz in the last century proposed that the source of the Sun's energy could be:

a slow contraction

The time it takes for the Sun to return to the same place in our sky after the Earth has rotated once is called:

a solar day

A large body in space that consistently makes its own light (instead of merely reflecting another body's light) is called

a star

A Hertz is

a unit of frequency

An astronomer observes two ordinary stars. The first one turns out to be twice as hot as the second. This means that the first one radiates:

about 16 times the energy of the second

Astronomers now think that there is a black hole with more than 4 million times the mass of our Sun at the center of our Galaxy? Roughly how large would the event horizon of such a supermassive black hole be?

about 17 times the size of the Sun

Roughly how many galaxies make up our Local Group?

about 60 or so

The atmospheric pressure at the surface of Titan is

about one-and-a-half times greater than the atmospheric pressure at earths surface

To go from a lower level in an atom to a higher level, an electron must

absorb a photon of energy

During the period we have daylight savings time, we

add one hour to local standard time

Two stars are giving off electromagnetic radiation. The hotter star will:

all choices here apply

Astronomers have found that the level of the Sun's activity varies over the centuries. How did they come to realize that this is so:

all of the above

The Population I stars in the Milky Way Galaxy

all of these

Which of the following stages will our own Sun go through in the future:

all of these

Why do many people consider Isaac Newton one of the greatest scientists who ever lived?

all of these answers apply

Which of the following has a longer integration time (can collect light for a longer period of time) than the human eye?

all the choices apply

We now know that the orbit of a stable planet around a star like the Sun is always in the shape of:

an ellipse

The geological process that we call tectonics refers to

any surface disruption, such as stretching or crumpling, caused by stresses within the interior of the world

As seen from the continental United States, the Big and Little Dipper

are in the north circumpolar zone throughout the year

The rings of Uranus

are narrow and dark.

The mountains on the Moon

are the result of giant impacts early in the Moon's history.

Which of the following statements about the life of a star with a mass like the Sun is correct?

as the star is dying, a considerable part of its mass will be lost into space

Which of the following statements about the violent events on the Sun called flares is FALSE?

astronomers think that flares are connected with sudden changes in the magnetic field of the Sun

An eccentric billionaire wants to build a mansion in a location on Earth where the effect of the seasons is the least pronounced -- where summer and winter are not that different. Where should his personal astronomer advise him to build?

at the equator

From a city in the U.S., where in the sky would you look to see a star that is not turning with the motion of the sky in the course of a night?

at the north celestial pole

Which of the following is a reason that astronomers have not found giant planets with the orbit of Neptune around other stars?

at the orbit of Neptune, only very low-mass planets (smaller than Mercury) can form

In the model that astronomers have developed for pulsars, why do they suggest that there must be two beams of energy coming from the pulsar

because neutron star beams come out of the north and south poles of a magnetic field

Imagine that a brilliant but quirky scientist in the biology department manages to put you in a deep freeze and you wake up in a million years. Which of the following statements about the sky you would see in that future time is correct?

because of proper motion, a number of the familiar constellations will look somewhat different in a million years

Some "superstars" give off more than 50,000 times the energy of the Sun. Why are there no such stars among the stars that are close to the Sun?

because such very luminous stars are extremely rare, and thus any small neighborhood in the Galaxy is unlikely to contain one of them

Why do telescopes have to have a good motorized drive system to move them quickly and smoothly?

because the Earth is rotating, with the telescope attached to it

Why do all stars spend most of their lives on the main sequence?

because the fuel for energy production in this stage of the star's life is hydrogen; and that is an element every star has lots and lots of

Why did it take astronomers until 1838 to measure the parallax of the stars?

because the stars are so far away that their annual shift of position in the sky is too small to see without a good telescope

Why can a star with a mass like our Sun not fuse (produce) further elements beyond carbon and oxygen?

because they just cannot get hot enough for the fusion of heavier nuclei

Two stars that are physically associated (move together through space) are called

binary stars

Galaxies that we see as they were 11 billion years ago or more, as compared to galaxies today, are generally:

bluer and smaller

In a science fiction television show set in the far future, a starship finds itself approaching a stellar association. What types of objects would they be most likely to notice in such an association as they approach?

bright O and B type stars

One key difference that astronomers use to distinguish between brown dwarfs and high-mass planets is that:

brown dwarfs are able to do deuterium fusion in their cores, while planets can't

How did Henrietta Leavitt "calibrate" her period-luminosity relationship for Cepheid variable stars? In other words, how did she make the general idea into a numerical rule?

by finding cepheids in star clusters whose distance was known in another way

At an astronomical conference, an astronomer gives a report on a star that interests astronomers because of hints that it may have a planet around it. In his report the astronomer gives the average speed with which this star is moving away from the Sun. How did the astronomer measure this speed?

by looking at the Doppler shift in the lines of the star's spectrum

Coronal Mass Ejections from the Sun have many serious effects on or near the Earth. Which of the following is NOT one of these effects?

causing huge cyclones around the equator of the Earth

Tectonic activity is

changes in a planet's surface due to forces from inside the planet.

The hotter region directly above the Sun's visible surface is called the

chromosphere

Recent spacecraft have found evidence of a small amount of water near the lunar poles, most likely deposited by ______ .

comet and asteroid impacts

Generally, the lunar surface is dominated by impacts; what produces its fine-grained soil?

continuing small impacts

The Earth has a global magnetic field, that is generated in the ________, produces Earth's magnetosphere, which can trap charged atomic particles.

core

Which part of the Sun's atmosphere is the hottest?

corona

Which of the following was NOT done by Hipparchus, the great ancient astronomer?

created the system of star magnitudes that we still use today

After a nice dinner around the campfire on a camping trip, you and a friend decide to get away from the fire to observe the stars. As you get farther and farther away, you see the brightness of the fire:

decrease as the distance squared

Which of the following factors determine how long it takes a planet to orbit the Sun?

distance from the Sun only

When neutron stars were first predicted theoretically, no scientist expected to be able to detect one of them across interstellar distances. What enabled astronomers to find neutron stars in the late 1960's?

e found strongly magnetic neutron stars whose whirling beams of energy were detected as pulsars

The fact that each type of atom has a unique pattern of electron orbits helps explain why

each type of atom shows different absorption or emission spectra

Which type of galaxy is observed to contain mostly older stars?

elliptical

After the core of a massive star becomes a neutron star, the rest of the star's material

explodes outward as a supernova

Mercury is the nearest planet to the Sun and the _______ compared to the rest of the planets around the Sun.

fastest moving

One of the main projects being carried out by the Hubble Space Telescope is to measure the distances of galaxies located in groups dozens of millions of lightyears away. What method do astronomers use with the Hubble to find such distances?

finding Cepheid variables and measuring their periods

Astronomers have noticed that the visible filaments in the Crab Nebula are moving toward us at great speed. How can they know about motions like this?

from the Doppler shift in the line radiation from the nebula

Astronomers believe that the large elliptical galaxies formed

from the collision and merger of many smaller fragments

During what phase of the Moon is the Moon up only during the night hours and all night long?

full moon

What do the surveys of the three-dimensional distribution of groups of galaxies reveal about how groups and clusters of galaxies are organized?

galaxy groups are organized into huge filaments with great voids between them -- something like the structure one would see taking a cross-section of some soap bubbles

The most widely accepted explanation for the origin of the Moon is the ________ hypothesis, which proposes that the Moon formed from an impact of a Mars-sized projectile with the Earth 4.5 billion years ago.

giant impact

What objects did Harlow Shapley use as "signposts" to figure out the extent of the Milky Way Galaxy and the location of its center?

globular clusters

In relation to the density of Earth's Moon, Mercury's density suggests that the planet

has a dense metal core.

The energy of random atomic and molecular motion is called

heat

If stars with masses like our Sun's cannot make elements heavier than oxygen, where are heavier elements like silicon produced in the universe?

heavier elements are made in the cores of significantly more massive stars than the Sun, which can get hotter in the middle

The granulation pattern that astronomers have observed on the surface of the Sun tells us that:

hot material must be rising from the Sun's hotter interior

Typically, astronomers express the right ascension of a star on the sky in what units?

hours, minutes, and seconds

Which of the following is a way that having an active galactic nucleus (AGN), with a supermassive black hole in the center, can affect the development of a galaxy?

huge energetic jets from the accretion disk can disturb and lessen star formation in the galaxy

The giant planets have dense cores roughly 10 times the mass of Earth, surrounded by layers of ___ and helium.

hydrogen

Which of the following characteristics match Europa

ice covered surface with few impact craters and surface features provide evidence of a subsurface liquid ocean

When you zoom in on the "Southern Highlands" of Mars, which geologic processes are most clearly evident?

impact cratering and erosion

When the BeppoSAX satellite, together with telescopes on the ground, helped astronomers pinpoint the location of the first gamma-ray burst to be identified with something that gave off visible light, the burst's location turned out to be in

in a distant galaxy

A science fiction writer needs an environment for her latest story where stars are as crowded together as possible. Which of the following would be a good place to locate her story?

in a globular cluster

If I want to find a sizeable collection of Population II stars in the Milky Way Galaxy, where would be a good place to look?

in a globular cluster high above the Galaxy's disk

If you want to find stars that are just being born, where are the best places to search?

in giant molecular clouds

Taking astronomy in college ruins you for having any kind of ordinary job, so after graduation you decide to become the leader of a new religious cult. You decide to hold a big religious festival around the time that the days are shortest and the nights are longest in the United States. During what month of the year will these celebrations be held?

in late December

Where would you look for the youngest stars in the Milky Way Galaxy?

in the disk

If hydrogen is the most common element in the universe, why do we not see the lines of hydrogen in the spectra of the hottest stars?

in the hottest stars, hydrogen atoms are ionized, and so there are no electrons to produce lines in the spectrum

If a galaxy contains a great deal of "dark matter," what will that do the galaxy's mass-to-light ratio?

increase it quite a bit

One similarity in the spectra of T dwarf stars and giant planets in our solar system is that their spectra show:

indications of methane

The Julian calendar made the significant advance of:

introducing the leap year, so that every fourth year had an extra day

According to the Cosmological Principle, the universe

is isotropic and homogeneous

Which of the following statements about Supernova 1987A is False?

it exploded relatively close to us, in a spiral arm of the Milky Way Galaxy

Which of the following statements about our best candidate for long-duration gamma-ray bursts is False?

it involves the merger of two black holes

Measurements show a certain star has a very high luminosity (100,000 x the Sun's) while its temperature is quite cool (3500o K). How can this be?

it must be quite large in size

How did astronomers determine that the planet orbiting the star HD 209458 is a gas giant like Jupiter and not made mostly of rocks or metals?

it took more than one of these measurements to figure out this problem

Astronomers must often know the distance to a star before they can fully understand its characteristics. Which of the following properties of a star typically requires a knowledge of distance before it can be determined?

its luminosity

How long a star remains on the main sequence depends most strongly on

its mass

Which of the following statements about the force of gravity is FALSE?

its strength is inversely proportional to the mass: the more mass, the less gravity

The number of degrees of arc that your location is north or south of the Earth's equator is called your:

latitude

In the Northern Hemisphere, the altitude (height in degrees above the horizon) of the North Star is always roughly equal to the

latitude of the observer

Saturn's rings look bright because

light from the Sun reflects off the material in the rings

There is some irony in the fact that the Hubble Space Telescope has shown that Edwin Hubble's classification scheme for galaxy shapes only works in the later stages of the universe. What have really deep pictures (going way back in time) taken with the Hubble Telescope shown about galaxies long ago (in the first few billion years after the Big Bang)?

long ago, galaxy shapes were not (for the most part) regular and organized; galaxies looks chaotic and lumpy

We have two waves of light, A and B. Wave A has a higher frequency than wave B. Then wave B must have:

longer wavelength

The most common kinds of stars in the Galaxy have

low luminosity compared to the Sun

Stars on the main sequence obey a mass-luminosity relation. According to this relation,

luminosity is proportional to mass to the fourth power (luminosity increases strongly with mass)

In figuring out the evolutionary tracks on the H-R diagram, astronomers

make model stars on a computer and then follow how their characteristics will change with time

Our planet's geology is dominated by plate tectonics, in which crustal plates move slowly in response to convection in the ________.

mantle

The planet Neptune was discovered by means of:

mathematical calculations of how it was perturbing the motion of a neighbor planet

To get the distance to a Cepheid variable star, astronomers must take several steps. Which of the following is not one of these steps?

measure the star's Doppler shift from its spectrum

The Global Oscillations Network Group (GONG) Project is engaged in:

measuring pulsations of the Sun from stations around the world

Radio astronomy has played a pivotal role in showing us the detailed structure of the Milky Way Galaxy. Which of the following techniques would a radio astronomer use as an essential part of an investigation of this structure?

measuring the Doppler shift of a line in a radio spectrum

An astronomer is observing a single star (and one which does not vary) which she knows is located about 30 light-years away. What was the most likely method she or her colleagues used to obtain that distance?

measuring the star's parallax

According to the geocentric view, everything in the heavens had to go around the Earth, which was the center of the universe. What objects did Galileo discover with his telescope that clearly didn't go around the Earth?

moons around the planet Jupiter

If a galaxy contains a great deal of dark matter, then, compared to the mass-to-light ratio of the inner part, the mass-to-light ratio of the whole galaxy will be

more

Most of the stars we can see with the unaided eye from Earth are

more luminous (intrinsically brighter) than the Sun

Astronomers were surprised to find so many Jupiter-mass planets so close to their stars. According to their best theories and models, such "hot Jupiters"

must have formed further out from the star and must have "migrated inward" early on

Astronomers have long realized that supernovae -- when they explode -- give off an enormous amount of light. But observations of Supernova 1987A (in the Large Magellanic Cloud) revealed that the supernova gives off even more energy in another form? That form is:

neutrinos

Which of the following statements about Supernova 1987A is False?

neutrinos from the explosion were actually detected on Earth

Crater counts can be used to derive approximate ages for geological features on the Moon and other worlds with solid surface. The more craters per unit area, the ________ the surface.

older

The original definition of a meter was

one ten-millionth of the distance from the Earth's equator to its pole

The Moon has about ________ the mass of Earth.

one-eightieth

An astronomer is interested in a galaxy called M31, the nearest galaxy that resembles our Milky Way. It is about 2 million lightyears away. Which technique would be able to give us a distance to this galaxy?

period-luminosity relation for Cepheid variables

You are out on the beach, enjoying the warm sunshine with friends. As you glance up at the Sun (only briefly we hope), the part of the Sun that you can see directly is called its:

photosphere

The material that would eventually make all the major bodies in our solar system first gathered together as smaller pieces, which astronomers call:

planetesimals

Within the solar nebula, material first coalesced into _________; many of these gathered together to make the planets and moons. The remainder can still be seen as comets and asteroids.

planetesimals

The material inside the Sun is in the form of

plasma

The antimatter version of an electron is called a

positron

I want to examine the surface of a planet that is covered by a thick atmosphere (which includes oxygen and contains a very thick layer of water clouds that never clears). What wavelength of electromagnetic radiation would I be smartest to use:

radar waves

The earliest telescopes used by astronomers were:

refractors

If you want to locate someone precisely on the surface of the Earth, you specify her exact latitude and longitude. If you want to locate a star precisely on the sky, you need to specify its exact:

right ascension and declination

Astronomer have concluded that pulsars are

rotating neutron stars

Your friend the werewolf only comes out when the Moon is full. He leaves a note for you, explaining that he can meet with you when the Moon is rising. What time of day will you be meeting the werewolf?

roughly around sunset

Earth is the prototype terrestrial planet. Its interior composition and structure are probed using

seismic waves

Most of what we know about the Moon derives from the Apollo program, including 400 kilograms of lunar samples still being intensively studied. It is _________ in both metals and volatile materials.

severely depleted

A graduate student has done a careful analysis of the spectrum of a star. While she has found lines from many elements, there was not a trace of the element helium in the spectra she has been analyzing. From this she can now conclude:

since helium shows lines only in hot stars, this star must be relatively cool

If there really were a Santa Claus at the North Pole, what would the cycle of the seasons be like for him and Mrs. Claus?

six months of light, followed by six months of darkness (or at least dark twilight)

Kuiper belt objects most closely resemble the moons of the jovian planets. This means that Kuiper belt objects are relatively _______ in size compared to other bodies in the solar system.

small

A white dwarf, compared to a main sequence star with the same mass, would always be:

smaller in diameter

When two light elements collide to undergo nuclear fusion

some energy in their mass is released

Astronomers observe a young cluster of stars, where stars with three times the mass of the Sun are still on the main sequence of the H-R diagram. Yet the cluster contains two white dwarfs, each with a mass less than 1.4 times the mass of the Sun. If we can show that the white dwarfs are definitely part of the cluster, how can their presence so soon in the life of the cluster be explained?

some stars can lose a lot of mass on their way to becoming white dwarfs; thus the white dwarfs could have started out as quite massive stars

Our Milky Way Galaxy is what type of galaxy?

spiral

An astronomer who is observing visible light from a glowing cloud of gas in space uses an instrument which contains a grating with thousands of grooves on its surface. What will this instrument allow our astronomer to do?

spread out the light from the cloud into a spectrum

When the Sun and Moon are lined up and pull together, the tides they raise are called:

spring tides

If you wanted to discover the youngest stars you could find in some grouping of stars in the Galaxy, which type of star group would be the best to search?

stellar associations

A "New Age" bride and groom, who are enchanted by the Sun, want to get married on the day when it gets to be highest in the sky. If they live in the United States, around what day of the year will the wedding take place?

summer solstice

photosynthesis is a complex sequence of chemical reactions through which some living things can use ________ to manufacture products that store energy (such as carbohydrates), releasing oxygen as one by-product

sunlight

Which type of star has the least amount of pressure in its atmosphere?

supergiants

Astronomical observatories have been available since ancient times, and many cultures set aside special sites for astronomical observations. The thing modern observatories have that was missing from these older observatories until about 1610 was:

telescopes

Wien's Law relates the wavelength at which a star gives off the greatest amount of energy to the star's

temperature

The instrument astronomers are now using to make the most precise measurements of stellar parallax we have ever had is

the Gaia satellite in space

Which of the following is Not part of the growing chain of evidence that makes many astronomers suspect there is a black hole at the very center of the Milky Way Galaxy?

the Hubble Space Telescope has shown us a visible-light image of an accretion disk at the center of the Galaxy

At which of the following locations on Earth is the direction we call East not clearly defined?

the North Pole

Which of the following is NOT an argument for showing that the Earth must be round:

the Sun is seen blocking different constellations in the course of a year

What mechanisms do astronomers believe is responsible for making the Sun's outer atmosphere so much hotter than its photosphere?

the Sun's magnetic field interacting with the charged particles that make up the atmosphere

Of the following, which has the highest resolution (ability to make out fine detail):

the Very Long Baseline Array of Radio Telescopes, stretching from the Virgin Islands to Hawaii

To establish the scale of the solar system, we need to measure the distance to one object orbiting the Sun. Venus was first used for this purpose, but in the 1930's astronomers organized an international campaign to measure the distance to:

the asteroid Eros

An astronomical unit is:

the average distance between the Earth and the Sun

Which of the following statements about the nuclear bulge of our Galaxy is False?

the best way to learn more about it is to observe higher energy radiation, such as ultraviolet and x-rays

Which of the following statements about our modern ideas of how spiral galaxies form and develop is True?

the central bulges of spiral galaxies formed first and their disks formed later

Which of the following are the small regions that are the embryos of stars (where individual stars are most likely to be

the cores within the clumps of molecular clouds

When an astronomer measures a color index for a star, what is she measuring?

the difference between how bright a star looks at two different wavelength regions

If observations of supernovae in other galaxies show that such an explosion happens in a spiral galaxy like the Milky Way on average every 25 to 100 years, why have astronomers on Earth not seen a supernova explosion in our Galaxy since 1604?

the disk of our Galaxy contains a great deal of dust, which tends to block the light of supernova explosions from more distant parts of our Galaxy

William Herschel thought that the Sun and Earth were roughly at the center of the great grouping of stars we call the Milky Way. Today we know this is not the case. What was a key reason that Herschel did not realize our true position in the Milky Way?

the dust that extends throughout the disk of the Galaxy only allowed Herschel to see the small part of the Milky Way that surrounds us

Which of the following is a characteristic of a white dwarf star?

the electrons get aour sos close to each other as possible and resist further compression

Mercury's long, tall cliffs are thought to have formed when

the entire planet shrank, causing the surface to crumple.

Edwin Hubble was able to show that (with the exception of our nearest neighbors) the farther a galaxy is from us, the

the faster it is moving away from us

If you could somehow return to the Earth in many millions of years, which of the following will be different?

the length of the month

The measurement of cosmic distances was helped tremendously by the discovery, in the early part of the 20th century, that in Cepheid variable stars, the average luminosity was related to:

the length of time they took to vary

The higher the luminosity (intrinsic brightness) a Cepheid variable is

the longer the period of its variations

A neutron star is as dense as

the nucleus of an atom

Which of the following is evidence that the formation process of our Galaxy may have included collisions with smaller neighbor galaxies?

the observation of long moving streams of stars that continue to orbit through our Galaxy's halo

Atmospheric circulation (weather) is driven by seasonally changing deposition of sunlight. Many longer term climate variations, such as the ice ages, are related to changes in __________.

the planet's orbit and axial tilt

Many names used by astronomers are misleading or outdated. A good example is the term planetary nebula, which astronomers use to refer to:

the shell let go by a dying low-mass star

Someone who observes the sky every clear night in Boston for many years will NEVER get to see:

the south circumpolar zone

When a star undergoes a nova explosion, it may return to its "quiet state" and later become a nova again. What would allow a nova explosion to happen to a star more than once?

the star that goes nova has a companion star near it, which dumps material onto the first star and continues to do so even after the first nova explosion

Which of the following characteristics of a single star (one that moves through space alone) is it difficult to measure directly?

the stars mass

What would you have to change about the Earth to stop our planet from having significantly different seasons?

the tilt of its axis

In a Type Ia supernova, the cause of the violent outburst is:

the transfer of so much mass from a companion star that a white dwarf goes "over the limit" and collapses, causing an enormous amount of sudden fusion

Of the following, which consists of electro-magnetic waves with the shortest wavelength?

the waves of a dental x-ray

Let's say we find a star that is located on the points or circles in the sky listed in the answer choices below. Then, on the same night, we move to a location on Earth that is some significant distance from our first location. There will now be a different star at or on:

the zenith

The strip of the sky through which the Sun, the Moon, and the bright planets appear to move in the course of a year is called:

the zodiac

When stars become giants, which of the following does Not usually happen?

their mass grows significantly as they incorporate planets and interstellar matter near the star

If it takes an average of 14 billion years before any proton inside the Sun will undergo fusion, and the Sun is only about 5 billion years old, why do astronomers believe that fusion is going on there now?

there are an enormous number of protons inside the Sun, and some of them will fuse much sooner than the average

Which of the following statements about forces is FALSE?

there are places on Earth where all forces are absent

Recently, astronomers have observed stars and other objects that orbit the center of the Milky Way Galaxy farther out than our Sun, but move around faster than we do. How do astronomers think such an observation can be explained?

there must be a great deal of invisible dark matter outside the orbit of the Sun whose gravitational pull explains the faster motions we see out there

Astronomers now have a good idea for explaining how the short-duration gamma-ray bursts might come about. Which of the following is part of their explanation?

these bursts most likely come from the merger of two neutron stars

Most of the really bright stars in our sky are Not among the stars that are very close to us. Why then do they look so bright to us?

these stars are intrinsically so luminous, that they can easily be seen even across great distances

Among irregular galaxies, what makes the Large and Small Magellanic Cloud especially useful for astronomers?

they are (for galaxies) very close to us, so they are easy to study

The reason type Ia supernovae are useful to astronomers for determining distances to other galaxies is that

they are very bright, and generally reach the same peak luminosity

How do astronomers know that pulsating variable stars are actually expanding and contracting in diameter?

they can measure a regularly varying Doppler shift in the spectral lines

Astronomers can now report that active star formation was going on at a time when the universe was only 20% as old as it is today. When astronomers make such a statement, how can they know what was happening inside galaxies way back then?

they examine the spectra of galaxies (or the overall colors of galaxies) with the highest redshifts they can find

Why do satellites launched into low-Earth orbits not remain there indefinitely?

they lose speed due to friction with the upper layers of the Earth's atmosphere

How do astronomers measure the mass that the Galaxy contains inside the orbit of the Sun?

they measure the distance to the center of the Galaxy and the period of the Sun's orbit and then use Kepler's Third Law

Our textbook discusses that radio astronomers are building more and more arrays of radio telescopes, where many "dishes" are connected together. What advantage do such arrays have?

they provide a higher resolution than individual dishes

Your sweetheart gives you a piece of gold jewelry as a present to celebrate your passing your astronomy class. Where did the gold atoms in that gift originally come from (where were they most likely made)?

they were built up from smaller nuclei during a supernova explosion

You and some friends decide (during a wild party held at the time of the Full Moon) that you cannot live without having the secret recipe for the veggie burger they serve in the college cafeteria. So you decide to plan a break-in to steal the recipe from the chef's office. So that you don't get caught, you want to carry out your plan when there is no moonlight in the evening. What is the next phase of the Moon with no evening moonlight (i.e. when the Moon rises roughly at midnight or later)?

third quarter

A light curve for a star measures how its brightness changes with

time

A star whose temperature is increasing but whose luminosity is roughly constant moves in what direction on the H-R diagram?

to the left

Circumstellar disks are a common occurrence around very young stars, suggesting that disks and stars form

together

Astronomers and physicists now believe they know what is happening to the missing neutrinos from the Sun (the neutrinos that our theories say should be emerging from the Sun, but our experiments in that underground mine could not find). These neutrinos are

turning into a different type of neutrino in a neutrino oscillation

All molecules (like molecules of water or carbon dioxide) are made up of

two or more atoms

In the summer of 1996, the European Space Agency announced that it would be suspending the operations of the International Ultraviolet Explorer. Astronomers who were most unhappy about that announcements were likely to be studying what types of objects?

very hot stars

How do astronomers know what the outer layers of the Sun are made of?

we take an absorption line spectrum of the Sun, and the absorption lines tell us what elements are present in the outer layers

Which of the following can we Not learn from studying the Doppler shifts in the spectrum of galaxies beyond our Local Group?

whether they have Jupiter-mass planets around many of their stars

When a single star with a mass equal to the Sun dies, it will become a

white dwarf

In the future, several students living on board a space station decide to have a race among different types of electromagnetic radiation. Which of the following travels through space the fastest?

you can't fool me, all of these travel through space at the same speed

Before you can use Hubble's Law to get the distance to a galaxy, what observation must you make of that galaxy?

you must take a spectrum of the galaxy and measure the red shift

The point in the sky directly above your head at any given time is called the

zenith

What is the baseline that astronomers use to measure the parallax (the distance) of the nearest stars?

½ the diameter of the Earth's orbit around the Sun