Review Questions Flashcards
1
Q
What is the altitude of the north celestial pole for an observer located on the earth’s equator?
A
0 degrees
2
Q
The zero point of longitude is
A
The prime meridian
3
Q
The angle measured up from the horizon is called the
A
altitude
4
Q
The point directly overhead is called the
A
zenith
5
Q
The two coordinates of the “celestial equitorial coordinate system” are
A
right ascension and declination
6
Q
What is the altitude of the north celestial pole for an observer standing on the north pole of the earth?
A
90 degrees
7
Q
The angle that measures north and south from the celestial equator is called the
A
declination
8
Q
Why were constellations essential for ancient peoples?
A
Constellations provided a calendar to support agriculture
9
Q
Latitude measures up/down from
A
the equator
10
Q
Describe how the stars in a constellation are connected to one another
A
They are completely unrelated to one another
11
Q
Which of the following was not listed as an unexpected benefit of astronomy research?
New methods for treating cancer
Theme park ride engineering
Medical and scientific imaging
X-ray scanners for airport security
A
New methods for treating cancer
12
Q
Professional astronomers, in general, know very few constellations in the night sky: T/F
A
True
13
Q
The length of the day on an equinox is
A
12 hours
14
Q
The change in seasons is caused by the change in the Sun’s
A
declination
15
Q
The path of the Sun on the celestial sphere is called the
A
ecliptic
16
Q
On the equator, the Sun will reach its highest point in the sky on
A
an equinox
17
Q
Which phase comes between waning gibbous and waning crescent?
A
third quarter
18
Q
If the moon is rising at midnight, what phase is it?
A
third quarter
19
Q
Which phase comes between new and first quarter?
A
waxing crescent
20
Q
If the moon is setting at noon, what phase is it?
A
third quarter
21
Q
Over the course of the year, the right ascension of the Sun
A
increases
22
Q
Which of the following planets exhibit the characteristic “back and forth” motion relative to the stars?
Venus
Jupiter
Saturn
All of the above
A
All of the above
23
Q
Which phase comes between waning crescent and waxing crescent?
A
new moon
24
Q
For an observer located on the equator, the azimuth of the stars due East will
A
stay the same
25
How can astronomers see stars right next to the sun?
with space telescopes
26
For an observer located on the North Pole, the altitude of the stars in the East will
stay the same
27
In the heliocentric model of the solar system, one planet passing another in its orbit gives rise to
retrograde motion
28
The time it takes a planet to orbit the Sun once and return to the same location in space is called the
sidereal period
29
Ptolemy's model of the solar system was by far the simplest and most elegant model: T/F
False
30
Ptolemy improved the geocentric model by
adding epicycles and deferents
31
The size of the Earth could be measured accurately in ancient times by using
shadows on Earth
32
Copernicus' heliocentric model was able to predict the location of the planets more accurately than Ptolemy's geocentric model: T/F
False
33
Ptolemy's improvements were important because they explained
retrograde motion
34
According to Newton's Law of Gravity, if two objects were to move twice as far apart, the force of gravity between them would be
four times smaller
35
The statement: "Planets move in ellipses with the Sun at one focus." is also known as
Kepler's First Law
36
Virtually no one acknowledged Kepler's work during his lifetime: T/F
True
37
The statement: "An object in motion will continue in motion unless acted on by an outside force." is also known as
Newton's First Law
38
Gravity between two objects is __________ proportional to the product of their masses and __________ proportional to the square of the distance between them
directly, indirectly
39
The key observation of Venus was that it exhibited a ________ phase
gibbous
40
The statement: "Planets sweep out equal area in equal time." is also known as
Kepler's Second Law
41
A complete physical theory to explain the motion of the planets was developed by
Newton
42
The statement: "A planet's orbital period squared is equal to its semimajor axis cubed." is also known as
Kepler's Third Law
43
The first proof that the Earth orbits the Sun was provided by
Galileo's observation of the phases of Venus
44
As you move farther away from a light source, its brightness will decrease at a rate
proportional to the distance squared
45
Which of the following regions of the electromagnetic spectrum has the greatest frequency?
x-ray
46
As the wavelength of a light wave gets bigger, the frequency
gets smaller
47
What two colors of light would you combine to make the color yellow?
red and green
48
When we look into the night sky, we are literally looking
into the past
49
What is the typical dynamic range of an astronomical image?
60,000:1
49
Regular jpeg images have only 256 "levels" available in each pixel, so they are considered
8-bit images
49
A digital camera is composed of _________ tiny pixels
millions of
49
Why do astronomers only take black and white images?
to maximize the resolution of their images
50
Which color of visible light has the longest wavelength?
red
51
Light pollution has been linked to which of the following? (Select all that apply)
Survival of specific bat species
Breast cancer rates in women
Negative changes to bird migration
Sea turtle hatchling survival rates
Survival of specific bat species
Breast cancer rates in women
Negative changes to bird migration
Sea turtle hatchling survival rates
52
The number of waves passing a point each second is the
frequency
53
Sitting on the table is a red book and a blue book. Which one is hotter?
They are probably the same temperature
54
Kirchoff's Laws suggest that emission lines in a spectrum are caused when
You are looking at a hot gas against a dark background
55
Star spectra contain
a continuous spectrum and absorption lines
56
The exact wavelength of the spectral lines of a gas cloud are determined by
the energy levels of the electrons within the gas cloud
57
A blackbody is a hypothetical object that.... (select all that apply)
is completely dark, giving off no light
absorbs all light that hits it
glows at a wavelength specified by its temperature
does not reflect any light
absorbs all light that hits it
glows at a wavelength specified by its temperature
does not reflect any light
58
The discovery of light "beyond the rainbow" is attributed to which scientist?
William Herschel
59
An an object gets hotter, it will
quickly get brighter
60
In order for an electron to move from one orbit to another, it must
emit or absorb light
61
In the sky, you see a red star and a blue star. Which one is hotter?
The blue star
62
Where did Earth's oceans come from?
Rain from water vapor in the early atmosphere
63
Which of the following provides observational evidence that Mars has weather and an atmosphere?
eroded craters
wind streaks
dust devils
all of the above
all of the above
64
Mercury has a network of strange wrinkles across its surface called
scarps
65
What molecules dominated the Earth's primordial atmosphere?
carbon dioxide and water vapor
66
Where did the oxygen in our atmosphere come from?
photosynthesis of living organisms
67
What factor most helps the Earth maintain a relatively constant temperature?
greenhouse gases
68
What initiated the runaway greenhouse effect on Venus?
The gradual warming of the Sun
69
The largest mountain in the solar system is
Olympus Mons
70
The surface of the moon contains geologic evidence for ___________ on the moon in the past
volcanoes
71
Which cities would be covered with water if the Greenland Ice Sheet melted completely?
Miami and Amsterdam
72
Why doesn't Mars have active volcanoes today?
the planet lost its internal heat to cold space
72
Mercury gets incredibly hot and incredibly cold because
it does not have an atmosphere
73
The bright circles around impact craters are called
ejecta
74
The appearance of Earth's moon is nearly identical to
Mercury
75
The best time to observe the moon to see its crater is during a
crescent moon
76
The discovery of _________ prompted astronomers to reconsider whether Pluto should really be called a planet
Eris
77
How many asteroids (that we know of) are on a potential collision course with Earth?
300 - 500
78
If a star is traveling toward you, its observed spectrum will be
blue-shifted
79
The Jovian planets are composed mostly of _______ and _________
hydrogen .... helium
80
If we could capture the spectrum of an exoplanet, we may find evidence for life on that planet in the form of
biosignatures
81
Why do some astronomers object to the new definition of a planet that was adopted in 2006?
By this definition, Earth, Jupiter, and other planets should not be considered planets
82
The gas in the solar nebula began at a temperature of about
2000 K
83
Which of the following parts of the formal definition of a planet does Pluto fail to meet?
It has cleared the neighborhood around its orbit
It is in orbit around the Sun
It is found in a roughly round shape
It is a celestial body
It has cleared the neighborhood around its orbit
84
Jupiter weighs roughly
twice as much as all the other planets combined
85
The _________ for discovering exoplanets looks for tiny dips in light as a planet passes in front of its star
Transit Method
86
What two factors influence whether gas particles stay or leave a planet's atmosphere?
gravity and heat
87
Almost the entirety of Jupiter's size is made up of
gas
88
The planets closest to the Sun are known as the
terrestrial planets
89
One way that we can observe changes in the overall magnetic dynamo of the sun is
the number of sunspots on the sun
90
The full moon has an apparent magnitude of roughly
-12
91
Sunspots were first observed
Before 300 B.C.
92
Sunspots are caused by
magnetic fields
93
Sunspots are dark because they are ___________ than the surrounding area
cooler
94
The mass of the sun is composed of about ______ hydrogen
75%
95
Every star, including our own sun, is powered by
nuclear fusion
96
Why was the parallax of the closest stars not observed until 200 years after the invention of the telescope?
The change in a star's position due to parallax is tiny and difficult to measure
97
The part of the sun that we see with our eyes is called the
photosphere
98
_____________ measures how bright an object would appear if it were exactly 10 parsecs away from earth
absolute magnitude
99
Parallax measurements of distant stars were dramatically improved with the use of
space telescopes
100
An HR Diagram of a star cluster shows that nearly all of the stars fall along the main sequence. From this information, we can tell that the star cluster must be
young
101
The horizontal axis of the HR Diagram is
temperature
102
What outward force balances against gravity in a star like our sun?
hot gas pressure
103
On a standard HR Diagram, stars with the largest radius will appear in the _________ corner
upper-right
104
What causes the bright beaming of radio waves coming from pulsars?
strong magnetic fields
105
Which of the following factors influences the luminosity of a star? (Select all that apply)
Temperature
Radius
Distance
Local gravity
Temperature
Radius
106
Pulsars appear to be rotating
hundreds of times per second
107
Which of the following stellar spectral types corresponds to the hottest stars
B
F
A
G
B
108
What is the key quantity that controls the evolution of a star?
mass
109
The total energy that a star produces in one second is known as the
luminosity
110
On a standard HR diagram, where would you find the most massive main sequence stars?
upper-left
110
Which of the following stars will take the longest to go from a protostar to a compact object?
10 solar mass star
5 solar mass star
100 solar mass star
1 solar mass star
1 solar mass star
111
The black hole at the center of the Milky Way has a mass of _________ solar masses
several million
112
The diagonal line across the middle of the HR Diagram is known as the
main sequence
113
The luminosity of a star can be determined by measuring the _____________ in the stellar spectra
width of the lines
114
When a star explodes as a supernova, the expanding gas can pass through the interstellar medium triggering
formation of new stars
115
Where could you find 300 billion of something in everyday life? (Select all that apply)
300 billion leaves on a tree
300 billion hairs on someone's head
300 billion blades of grass in a typical yard
300 billion grains of sand at the beach
300 billion grains of sand at the beach
116
If you do not account for ____________, you may conclude that the distribution of stars in the sky provides evidence that we are located at the center of the Milky Way
dust
117
Dark matter is found in
in every type of galaxy
117
Which of the following statements best describes the mass in the outer parts of the Milky Way (beyond the orbit of the sun)?
There is essentially no mass out there
The outer part of the galaxy is rapidly evaporating into intergalactic space
It emits a surprisingly small amount of light
Most of the mass is due to a super-massive black hole
It emits a surprisingly small amount of light
118
Which equation(s) are used to detect the presence of dark matter in galaxies?
Doppler shift equation
Kepler's 3rd Law
Wien's Law
A and B
A and B
119
What evidence do we have that there is dark matter in the galaxy?
Flat rotation curves far from the center of the galaxy
120
Which of the following provides clear evidence for dark matter? (Select all that apply)
gravitational lensing
supernovas
Cepheid variable stars
galaxy rotation curves
gravitational lensing
galaxy rotation curves
121
Cold clouds of gas and dust between stars are called
molecular clouds
122
The mass of our galaxy has been found by
applying Kepler's Third Law to the Sun's orbit
123
The distance to the center of our galaxy can be found from
mapping the distribution of globular clusters
124
How many stars are in the Milky Way?
300 billion
125
Which of the following statements about interstellar dust is FALSE
dust makes distant stars look fainter than they should
dust scatters blue light from stars
dust makes distance stars look redder than they should
dust gives HII regions their red color
dust gives HII regions their red color
126
When the sun passes through densest parts of the galaxy, we risk
other stars catapulting comets toward the earth
127
Which of the following is NOT a possible explanation of dark matter?
Dark matter is so cold that it does not shine bright enough for us to see it
128
The Hubble Tuning Fork diagram proves that galaxies gradually move from being elliptical galaxies to spiral galaxies over time: T/F
false
129
Which of the following is NOT a type of galaxy identified by Hubble?
barred spiral
irregular
circular
elliptical
circular
130
The cosmic distance ladder begins with the most direct measurements of distance, such as
parallax
131
How can astronomers be sure that their measurements of distances to galaxies are accurate?
They measure the distance using multiple independent methods
132
Supernovas are particularly useful as distance indicators because
they can be seen from very far away
133
A galaxy that looks like a smooth squashed sphere would like be classified as a(n) __________ galaxy
elliptical
134
If a galaxy were shrunk down to the size of a paper plate, then the next nearest galaxy would be
less than 100 ft away
135
Which scientist used Cepheid variables to measure the distance to faint "nebulas" in our sky, proving they were actually whole other galaxies?
Edwin Hubble
136
Cepheid variables make good standard candles because their period is closely related to their _____________
absolute magnitude
137
The difference between the apparent magnitude and the absolute magnitude is known as the
distance modulus
138
How did Hubble and others measure the speed of galaxies moving through space?
The Doppler Effect
139
Hubble was able to prove that galaxies are very far away because he
discovered Cepheid variables in galaxies
140
How can astronomers measure the age of the universe from the speed and distance of a single galaxy?
distance / speed
141
The two engineers who discovered the cosmic microwave background worked for
a phone company
142
Before Hubble's measurement of the distances to galaxies, astronomers thought that the entire universe was the size of
The Milky Way Galaxy
143
The cosmic microwave background allows us to talk about the "temperature of the universe." What is roughly the temperature of the universe today?
3 Kelvin
144
What are the three primary pieces of evidence supporting the big bang (select three)
The cosmic microwave background
Olber's paradox
Universal expansion as shown by Hubble's Law
The abundance of the lightest elements by initial fusion in the big bang
The cosmic microwave background
Universal expansion as shown by Hubble's Law
The abundance of the lightest elements by initial fusion in the big bang
145
Edwin Hubble single-handedly made all of the discoveries necessary to prove that our universe is expanding: T/F
false
146
The idea of the big bang model was first proposed by
Georges Lemaitre
147
What are the axes of the graph of Hubble's Law?
velocity vs distance
148
Most astronomers believe that space ends at the edge of the observable universe: T/F
false
149
The curvature of space as a whole is primarily determined by
Omega-M
150
According to astronomers' best measurements, space appears to be
flat
151
What source of data leads us to believe that the cosmological constant is not equal to zero?
supernovas
152
According to the Carl Sagan music video, what is the first step in making an apple pie from scratch?
invent the universe
