Starry Nights (Chapter One, Two, Three, and Four)

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

From horizon to opposite horizon, the sky takes up how much angular distance?

180 degress

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

230 years ago

Light travels 3 x 10^8 meters every second (after rounding). That number in words is

300,000,000 meters

Credit for the discovery of Neptune is shared by two astronomers. They are:

Adams and Leverrier

What problem has precession caused for many of the schools of astrology? a. Because of precession, the stars making up the constellation figures (like Leo the Lion) have moved so far apart, they no longer look like their names b. Because of precession, Mars no longer shows retrograde motion and so all the horoscopes done using Mars turn out to be wrong c. Because of precession, some of the planets that astrologers use to construct horoscopes no longer orbit the Sun d. Because of precession, the constellations are no longer lined up with the astrological signs that are named after them; since astrology was set up, the two have slipped one sign apart e. You can't fool me, precession has not affected anything about astrology

Because of precession, the constellations are no longer lined up with the astrological signs that are named after them; since astrology was set up, the two have slipped one sign apart

The Renaissance astronomer who wrote the pioneering book that suggested the Earth probably orbits the Sun (instead of the other way around) was:

Copernicus

In an ellipse, the ratio of the distance between the foci and the length of the major axis is called:

the eccentricity

The Sun's apparent path around the celestial sphere is called

the ecliptic

For scientists, an element (like gold) is defined by

the number of protons in its nucleus

The celestial sphere turns once around each day because

the planet on which we live is rotating

After a long night of cramming for a test, your college room-mate hits his head forcefully against the wall of your room in despair. According to Newton's 3rd Law, as he exerts a force against the wall, there must be an equal and opposite force. How does that opposite force show itself in this case?

the wall exerts a force on your room-mate's head and he has a headache

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

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

two or more atoms

Astronomers discover a new comet that orbits the Sun, but has its aphelion (the furthest point in its orbit) beyond Neptune. Astronomers studying this comet have the right to expect that it:

will follow Newton's laws of motion

A single star in the process of forming starts by spinning slowly (while it is quite large and relatively cool.) As the star collapses under the pull of its own gravity, its size decreases. As a result, its rate of spinning:

will increase

Which of the following is the Earth NOT located in? a. the solar system b. the milky way c. the local group of galaxies d. the virgo supercluster e. you can't food me, we are located in all of the above

you can't fool me, we are located in all of the above

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

Sputnik

Someone who observes the sky every clear night in Boston for many years will NEVER get to see: a. the south circumpolar zone b. the north celestial pole c. the observer's zenith point d. the north circumpolar zone e. the Big Dipper

a. the south circumpolar zone

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

By the term universe, astronomers mean

everything that we can observe

The Astronomical Unit (AU) as defined by astronomers is

the average distance between the Earth and the Sun

A light year is

the distance that light travels in one year

Newton's reformulation of Kepler's third law allows us to measure the masses of bodies in orbit around each other, if we can measure:

the distances and periods of revolution

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

zenith

The great astronomer of ancient times who summarized and improved a system of circles upon circles to explain the complicated motions of the planets (and published the system in a book now called The Almagest) is:

Ptolemy

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

The smallest piece of an element (like gold or lead) that still has all the properties of that element is called

an atom

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

an ellipse

Where on Earth do stars always circle the zenith (and never rise and set)?

at the north pole

Which ancient Greek thinker suggested (long before Copernicus) that the Earth is moving around the Sun? a. Aristotle b. Aristarchus c. Eratosthenes d. Hipparchus e. Zorba

b. Aristarchus

According to Kepler's 2nd Law, comets (which have eccentric orbits) should spend a lot more of their time:

far from the Sun

When it comes to our place in the solar system today, which model do we accept?

heliocentric

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

hours, minutes, and seconds

You are on a camping trip, far away from city lights. You look up into the dark night sky, and see lots of stars, some brighter, some dimmer. All the stars you see with your unaided eye are

in the Milky Way Galaxy

The idea that objects (in the absence of an outside force) tend to continue doing what they are already doing is called the law of

interia

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

In locating objects on the celestial sphere, we call the number of degrees east or west that something is from Greenwich, England its:

longitude

The planet Neptune was discovered by means of:

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

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

The laws of nature (as determined by scientists) a. are constructed from many b.observations, hypotheses, and experiments c. apply both on Earth and among the stars d. can never, ever change once they are written down in textbooks e. are often written in the language of mathematics f. more than one of the above

more than one of the above

When a planet, in its orbit, is closer to the Sun, it:

moves faster than average

When a comet like Comet Hale-Bopp comes closest to the Sun in its orbit, we say that it is at:

perihelion

Small changes in the orbits of planets caused by the gravitational pull of the other planets in the solar system are called:

perturbations

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

The south celestial pole and the north celestial pole lie in the sky directly above

the Earth's axis

If the Earth goes around the Sun, why is the ecliptic not lined up with the celestial equator?

the Earth's axis is tilted by about 23 degrees from the vertical

Every celestial object appears to go around the Earth once a day. In addition to this motion, which celestial object has the fastest apparent motion in the sky?

the Moon

Why do astronauts (and cans of soft drink) float around in the Shuttle instead of falling?

the Shuttle is falling around the Earth (and everything aboard is in free fall)

The star that provides energy for life on Earth is

the Sun

In Ptolemy's system the planets orbit the Earth and not the Sun. How did the system explain the retrograde motion of planets like Jupiter?

the planets moved on a small circle whose center, in turn, circled a point near the Earth

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

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

Of these, which is the closet to us?

The Moon

The slow tipping of the Earth's axis in a circle with a period of about 26,000 years is called:

precession

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

the North Pole

Within a constellation, a smaller, recognizable pattern of stars is often called:

an asterism

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

are in the north circumpolar zone throughout the year

The scientist who first devised experimental tests to demonstrate the validity of the heliocentric model of the solar system was

Galileo

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

Greenwich, England

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 everywhere must obey

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

Mercury

The planet in our solar system whose orbit actually brings it inside the orbit of another planet is:

Pluto

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

Polaris

Of these, which is the largest?

The Universe

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

The moon

The 17th century astronomer who kept a roughly 20 year continuous record of the positions of the Sun, Moon, and planets was:

Tycho Brahe

What specific event really made it possible for the three laws of planetary motion to be discovered?

Tycho Brahe died and his assistant was able to get full access to his data

Newton showed that to change the direction in which an object is moving, one needs to apply:

a force

The location of the Earth in the Milky Way Galaxy is

a little less than 30,000 LY from the center

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

a star

The astroid belt is:

a zone where rocky chunks orbit between Mars and Jupiter

Based on the scientific and statistical tests of astrological predictions, which of the following statements is the most reasonable? a. astrology has passed every test with flying colors and scientists now agree that the positions of celestial objects are very important in determining our personalities and future b. astrology has not passed any clear scientific or statistical test and, as a result, most scientists are very doubtful that it can predict anything meaningful about our lives. astrology has passed about half of the tests that have been devised for it, and it is very controversial; about half the scientists think it works, and the other half do not d. no one has ever tested astrology, so it is not possible to say whether it is a useful predictive tool e. because it was Ptolemy who wrote the books on which modern astrology is based, most scientists believe it must be correct, no matter what any tests reveal

b. astrology has not passed any clear scientific or statistical test and, as a result, most scientists are very doubtful that it can predict anything meaningful about our lives

In what fundamental way did the work of Galileo differ from his predecessors who had thought about the sky? a. Galileo consulted many authorities before coming to scientific conclusions, instead of working on his own b. Galileo translated the works of the ancient Greek astronomers, and relied on their wonderful abilities to think through difficult problems c. Galileo used instruments and experiments to show him what nature was doing, instead of relying on pure logic d. Galileo relied on the revelations of the Bible to tell him what was happening in the sky e. Galileo believed that the Earth was the center of the solar system, and everything revolved around it

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

Which of the following statements about the force of gravity is FALSE? a. it is a universal force, which acts everywhere in space b. its strength decreases as the square of the distance c. its strength is inversely proportional to the mass: the more mass, the less gravity d. the force never becomes zero e. it causes the paths of the planets to be ellipses and not straight lines

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

When a planet temporarily moves westward in the sky over the course of several weeks or months (instead of eastward, as it typically does), we call it: a. precession b. ecliptic motion c. retrograde motion d. circumpolar motion e. rude

c. retrograde motion

To come up with the precise mathematical form of his law of gravity, Newton first had to invent the mathematical techniques that we now call:

calculus

On the celestial sphere, halfway between the celestial poles lies the

celestial equator

The minimum speed required to launch an object so that it remains the same distance above the ground and just falls around the Earth is called:

circular satellite velocity

The 88 sectors into which astronomers today divide the celestial sphere (the whole sky) are called:

constellations

Why do many people consider Isaac Newton one of the greatest scientists who ever lived? a. He formulated the laws that govern all motion in the universe b. He combined the work of Galileo, Brahe, and Kepler into one framework c. He figured out the mathematical form of a law of universal gravity d. all of the above e. none of the above (not a, not b, not c)

d. all of the above

A graduate student in geology who grew up in Florida (near the southernmost tip of the United States) gets to accompany her research professor to the North Pole. What will be different at the North Pole from the way she remembers the sky in Florida? a. the celestial pole is overhead b. the celestial equator is on the horizon c. the way (and whether) the stars rise or set d. all of the above would be different from the way it is in Florida e. all of the above (a - c) would be the same as in Florida

d. all of the above would be different from the way it is in Florida

How did Eratosthenes measure the size of the Earth? a. by walking about one-quarter of the way around its circumference b. by measuring the times of sunrise in each of the four seasons c. by determining the parallax of the Moon and finding the size of its orbit d. by measuring the height of the Sun in the sky on the same day in two cities at different latitudes e. by asking Aristotle who knew everything

d. by measuring the height of the Sun in the sky on the same day in two cities at different latitudes

Which of the following was NOT done by Hipparchus, the great ancient astronomer? a. compiled a pioneering catalog of the positions of hundreds of stars b. created the system of star magnitudes that we still use today c. discovered that the Earth has a motion called precession d. explained retrograde motion e. you can't fool me; Hipparchus did all of the above

d. explained retrograde motion

Which of the following is NOT a result of the Earth's precession? a. the Earth wobbles (like a spinning top) with a period of 26,000 years b. where the Earth's axis points in the sky changes over the centuries and millennia c. Polaris will no longer be the North Star in several thousand years d. the stars twinkle when seen from the surface of planet Earth e. the signs of the zodiac most astrologers use are no longer in accord with the constellations in which the Sun is currently found over the course of the year

d. the stars twinkle when seen from the surface of planet Earth

According to Kepler's third law, there is a relationship between the time a planet takes to revolve around the Sun and its

distance from the Sun

The way scientists know that a hypothesis in astronomy is a reasonable description of nature is to

do experiments and observations about the predictions of the hypothesis

Which of the following is NOT an argument for showing that the Earth must be round: a. during an eclipse of the Moon, the shadow of the Earth is always seen to be round b. when ships travel a large distance away, we see their hulls disappear first and their masts disappear last c. the height of the North Star changes as we travel to different latitudes d. photographs of the Earth from space always show a round body e. the Sun is seen blocking different constellations in the course of a year

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

To leave the gravitational pull of the Earth, and explore other planets, satellites must have at least:

escape velocity

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

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? a. Copernicus said that the presence of a large Moon kept the Earth from flying apart. b. Copernicus argued that God would never allow a planet with people to be exposed to that kind of danger c. Copernicus said that the Earth also orbits the Sun, and the motion around the Sun keeps the many parts of the Earth together d. 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 e. You can't fool me, Copernicus never thought that the Earth was rotating

d. 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

Even with the best and largest telescopes, we can't see all the stars in the Milky Way Galaxy, even though these same telescopes can show us other galaxies. Why is that?

dust in the space between stars builds up over large distances and blocks the light of stars behind the dustier parts of the milky way

Which of the following has the greatest density? a. a cubic meter of snow b. a cubic meter of air c. a cubic meter of astronomy textbooks (the printed versions, not the on-line ones) d. a cubic meter of feathers e. a cubic meter of lead

e. a cubic meter of lead

Which of the following was NOT done by Galileo Galilei? a. turning the telescope to the sky and believing what it showed his eyes b. discovering four large moons around Jupiter c. discovering that Venus goes through phases (like the Moon) d. resolving the Milky Way into many, many stars e. explaining retrograde motion with the heliocentric hypothesis

e. explaining retrograde motion with the heliocentric hypothesis

In Newton's Law of Gravity, the force of gravity goes up as the: a. mass goes down b. distance goes up c. mass goes up d. distance goes down e. more than one of the above

e. more than one of the above

Some Canadian troops are sent (as part of a U.N. peacekeeping force) to a country located on the Earth's equator. At night, when homesickness makes them gaze sleeplessly at the stars, which of the following will be familiar to them (the same at the equator as in Canada): a. the celestial poles are on the north and south points of the horizon b. the celestial equator is overhead and passes through the zenith c. all stars rise and set (no star remains in the sky all night long) d. all stars are above the horizon exactly half a day e. none of the above are the same on the equator as in Canada

e. none of the above are the same on the equator as Canada

Which of the following statements about forces is FALSE? a. forces change the momentum of a body b. forces cause an acceleration to take place c. forces always occur in equal and opposite pairs d. where there is no force, objects continue to move the way they were moving e. there are places on Earth where all forces are absent

e. there are places on Earth where all forces are absent

To figure out what you weigh on the surface of the Moon (how much gravity there pulls you downward), you need to know a. just the mass of the Moon b. just the distance from the Moon's center to its surface c. just the size of the Moon's orbit around the Earth (its semi-major axis, say) d. which part of its orbit the Moon is in e. two of the above factors

e. two of the above factors