Final Exam Flashcards
(164 cards)
1
Q
If you were to specify your adress in the universe, listing your membership from the smallest to the largest physical structures, it would be
A
earth, solar system, milky way, local group, virgo supercluster, the universe
2
Q
Our universe is approximately ____ years old
A
14 billion
3
Q
The astronomical unit (AU) is a distance based on
A
the distance from the earth to the sun
4
Q
a light year is measured in units of
A
distance
5
Q
after the sun, the next nearest star to us is approximately ____ away
A
4 light years
6
Q
one of the nearest stars is alpha centauri, whose distance is 4.4 light-years. the time it takes light to travel from alpha centauri to us is
A
4.4 years
7
Q
the scientific method is a process by which scientists
A
gain confidence in theories by failing to prove them wrong
8
Q
the line running directly overhead from north to south of an observer defines his/her
A
meridian
9
Q
no matter where you are on earth, stars appear to rotate about a point called the
A
celestial pole
10
Q
the celestial north pole has a declination of
A
90 degrees N
11
Q
how is the measure of declination best described
A
coordinate on the celestial sphere similar to latitude on the earth; measured in degrees N or S of the celestial equator
12
Q
how is the measure of right ascension best described
A
coordinate on the celestial sphere similar to longitude on the earth; measured in hours and minutes from the intersection of the ecliptic and celestial equator at vernal equinox
13
Q
if you see a star at 9 PM, the same star will be in a different position at 10 PM the same night. What causes this motion
A
the earth’s rotation on its axis
14
Q
my meridian at 9 PM is a RA= 1h, and a given star is at RA= 2h. What time will that star be at my meridian?
A
10 PM
15
Q
if the star polaris has an angle of 35 degrees above the north horizon, then we know that
A
our latitude is at +35 degrees
16
Q
the apparent path of the sun across the celestial sphere during a year is called the
A
ecliptic
17
Q
the sidereal day is one rotation with respect to the ___. It is __
A
stars; 23 hours 56 min
18
Q
planets in our solar system
A
appear near the ecliptic in our sky
19
Q
the constellations of the zodiac have special significance in astronomy because
A
the lie along the ecliptic
20
Q
we experience seasons because
A
the earth’s equator is tilted relative to the plane of the solar system
21
Q
the effects which make parts of the earth warmer in the summer are
A
the earth receives more or less direct sunlight due to the tilt of its axis and the number of daylight hours is longer in the summer and shorter in the winter
22
Q
which of the following applies to the equinoxes
A
the sun lies directly in line with the earth’s equator, the ecliptic is crossing the celestial equator, the length of daylight is equal to the length of night
23
Q
where is the moon in relation to the earth and the sun during the new moon
A
between the sun from the earth
24
Q
where is the moon in relation to the earth and the sun during the first quarter
A
25
when will the full moon rise
6pm
26
when will the third quarter rise
midnight
27
the moon completes a full cycle of phases roughly every month. In order for us to always see the same physical surface of the moon it must rotate
once every month
28
during which lunar phase can solar eclipses occur
new
29
during which lunar phase can lunar eclipses occur
full
30
why don't solar eclipses occur every month
the moon must be on the plane of ecliptic for an eclipse to occur
31
what is a blue moon
it is the second full moon phase in a singular calendar month
32
geocentrism states that
objects in the solar system orbit the earth
33
planets in our sky occasionally appear to reverse their motion from day to day. This is called
retrograde
34
what contemporary astronomer promoted heliocentrism but failed to convince due to his assumption of circular orbits
Nicolaus Copernicus
35
what contemporary astronomer provided the precise observations which eventually led to our current understanding of motion in the solar system
Tycho Brahe
36
the eccentricity of a planets orbit indicates
how much the orbit stretched rom circular
37
Keplers first law states that the orbit of a planet is
an ellipse with the sun at one foci
38
keplers second law states that a line connection a planet to the sun sweeps and equal area in equal time. This implies that planets
travel faster when near the sun
39
keplers third law indicates that
planets further from the sun have longer years
40
what contemporary astronomer made telescopic observations that supported heliocentrism
Galileo Galilei
41
Newtons first law states that if the sun suddenly disappeared, the earth would
move in straight line at constant speed
42
in which of the following situations would the object be experiencing an unbalance (net) force
a car moving a constant speed turning a corner
43
if an unbalanced force acts on an object, then the objects motion changes. How is the force related to accelerations
directly proportional
44
if the same size force acts on two sperate objects, which one would accelerate more
the one with less mass
45
the size of force exerted on the sun by the earth
is the same as the force exerted on the earth by the sun
46
the gravity of the earth pull down on a man. according to newtons third law, what is the other half of this pair of forces
the mans gravity pulling up on the earth
47
in the absense of air friction, a 0.001-kg piece of paper and a 0.1-kg notebook are dropped from the same height and allowed to fall to thr ground. How do their accelerations compare
the accelerations are the same
48
which of the following properties of an astronaut changes when he/she is standing on the moon, relative to when the astronaut is standing on earth
weight
49
if the separation doubles between two objects, the effect of gravity is ___ of the original
one-fourth
50
the speed of light is about
300 million m/s (3x10^8 m/s)
51
as frequency increases, the energy of a photon __ and its wavelength __
increases; decreases
52
as wavelength decreases, the energy of a photon ___ and its frequency ___
increases; increases
53
how does the wavelength and frequency of red light compare to the that of blue light
red light has a longer wavelength and lower frequency than those of blue light
54
The nucleus of an atom contains
protons and neutrons
55
Angular resolution is the ability to
distinguish between closely spaced objects/features
56
Refraction is caused by
light traveling at different speed in different materials
57
Light travels in materials at a speed
less than c
58
refractors use ____ as the primary light collecting object
lenses
59
reflectors use ___ as the primary light collecting object
mirrors
60
the light gathering power of a ground-based refractor is usually set by:
primary lens area
61
the angular resolution of a ground-based refractor is usually set by:
primary lens diameter
62
longer wavelengths make angular resolution
worse
63
what is the biggest difficulty in detecting (on the earth) infrared photons from an astronomical source
carbon dioxide
64
ultraviolet radiation is hard to observe on the earth primarily because
oxygen (ozone) in the earth's atmosphere easily absorbs it
65
ranges of wavelengths that freely pass through our atmosphere are called
atmospheric windows
66
why do radio telescopes need to be very large
to compensate for the loss in angular resolution due to long wavelengths
67
especially dense, cold regions of gas and dust where molecules can form are
molecular clouds
68
as molecular clouds collapse due to ___, ___ tends to push them apart
gravity, pressure
69
the "ever changing balance" in a protostar is called
hydrostatic equilibrium
70
what distinguishes (is different in) a star from a protostar
fusion
71
protostars which never reach high temperatures necessary for fusion are called
brown dwarfs
72
blackbody radiation can be used to determine the ___ of an object
temperature
73
conservation of angular momentum slows a clouds collapse
mostly along directions perpendicular to the clouds axis of rotation
74
why do all of the planets orbit the sun in the same plane (plane of the ecliptic)
early during formation, the gas collapsed into a plane and then formed planets
75
planets in the inner solar system lack significant amounts of ___ materials available to the outer planets. They instead consist primarily of ___ materials
volatile; refractory
76
whether or not a planet is composed mostly of rock or gas is determined by
its mass, the distance from the star that it orbits, and its temperature
77
density is __
mass divided by volume
78
obliquity is ___
the tilt of the angle of rotation
79
what is not a reason the earth has very few craters on the surface
we are not hit very often
80
carful study of cratering on the moon revealed that impacts were
most common in the first billion years of the solar system
81
radiometric methods allow us to determine
absolute age
82
the half life of a radioactive material is
the time it takes for half the material to decay
83
what mechanism is primarily responsible for tectonics on earth
convection
84
which of the following objects have water on the surface
neither venus, mars, or the moon
85
differentiation refers to the materials that are separate based on their
density
86
which of the following does not provide information about the earths innermost layers
excavation
87
how does newtons law of universal gravitation allow us to determine the mass of planets
measure its effect on orbiting objects
88
the earths core is comprised mostly of
iron
89
Tidal forces are defined as those which:
act differently on a body
90
what is the best explanation prolonging the heating of the earths interior
the tidal effects of the moon
91
the current theory is that a planet will have strong magnetic fields if it has
fast rotation and conducting liquid core
92
the extremely slow rotation of venus is likely reason it
has no magnetic field
93
the most widely accepted theory for the formation of our moon is
collision theory
94
Venus and Mars have atmospheres consisting mostly of nitrogen and
carbon dioxide
95
The only other terrestrial planet with large amounts of oxygen in it's atmosphere is
venus
96
The main greenhouse gases in the atmospheres of the terrestrial planets are:
carbon dioxide and water vapor
97
Greenhouse gasses in the atmosphere result in:
all of the above
98
What is the main driver that causes Hadley circulation in a planet’s atmosphere to break up into zonal winds?
the planets rapid rotation
99
What causes circulation of air from the Equator to circulate to the Poles (Hadley circulation)?
convection driven by solar heating
100
The average density of the Giants is most closely comparable to
water
101
The compositions of the Ice Giants differ from the Gas Giants in that they contain more:
water and methane ices
102
The Gas Giants are composed primarily of
hydrogen
103
The inner core of each of the giant planets is made up of rocky material that is from __________ times the mass of
the Earth.
5 to 20
104
Uranus and Neptune appear blue due to the absorption of long wavelengths and diffuse reflection of blue
wavelengths from ________ in their atmosphere
methane
105
In general, as pressure increases in a body, temperature ________ .
increases
106
Liquid under low pressure would tend to transform to _______. Liquid at low temperature would tend to transform
to ________.
gas; solid
107
Despite the high temperatures in the interior of giant planets, their interiors remain liquid (instead of gas) because:
they are under very low pressures
108
We refer to some of the inner regions of Jupiter and Saturn as metallic hydrogen because they:
efficiently conduct electricity
109
Ring material most likely originates from:
moons disrupted by tidal forces
110
Eris and Pluto are examples of what class of object:
dwarf planets
111
What IAU criteria of a planet does Pluto fail?
cleared orbit of other objects
112
Io remains geologically active due to
tidal forces
113
The Asteroid belt is where in our Solar System?
between orbits of mars and jupiter
114
Short period comets come from a band of objects in the plane of the ecliptic at the edge of the solar system named:
the kuiper belt
115
Which of the following does NOT describe comets in the Oort Cloud?
within the plane of ecliptic
116
Comets are highly visible in the inner solar system because?
vaporized material forms an enormous "atmosphere" (coma) which efficiently reflects light
117
Light phenomena observed as small particles of debris burn-up in our atmosphere are called
meteros
118
Objects from space which reach the surface of a planet are called
meteorites
119
The cause of parallax is
that objects appear to shift position when viewed from different perspectives.
120
Parallax is used to measure
distance
121
The parsec is a measure of
distance based on the measure of parallax angle for stars obtained when the Earth is on either side of the Sun.
122
What is the difference between apparent and absolute brightness?
Apparent is the observed brightness; absolute is adjusted for the effect of distance
123
Stars A and B have the same luminosity, but star A is twice as CLOSE as star B. Which of the following is true?
Star A appears four times as bright as star B.
124
Star A is a red star. Star B is a blue star. Which is hotter?
star B
125
A star emits (prior to passing through any other gas/material):
a continuous spectrum (blackbody radiation)
126
When a continuous spectrum passes through a "cool gas" some wavelengths are absorbed. This reveals what
property of the gas
chemical composition
127
When an absorption spectrum for an element has wavelengths shifted. This reveals what property of the gas
velocity
128
When the wavelengths of an absorption spectrum are shifted to longer values, this is called
redshift
129
Spectral class is used to represent which property
temperature
130
The Hertzsprung-Russell diagram is:
a graph of luminosity versus surface temperature for stars
131
Very hot, dim stars are found at the ___________ of the HR diagram
lower left
132
Very large, cool stars are found at the
upper right
133
Very small, cool stars are found at the
lower right
134
What property can be read directly from an H-R diagram only for main sequence stars.
mass
135
The majority of the Sun’s energy comes from:
hydrogen fusion
136
Main sequence stars are defined by the fact that they
are fusing hydrogen into helium in their core
137
Einstein's famous equation E=mc2
indicates
the amount of energy in conversion of mass
138
. Moving away from the core of the Sun, energy is first transported by ____ and then _______
radiation; convection
139
One of the ways we confirm that the Sun is powered by proton-proton fusion is by studying
neutrinos
140
The portion of the Sun from which we receive most of our light is called the
photosphere
141
The solar cycle refers to
an 11-year period over which frequency of sunspots varies
142
The Maunder Minimum was a roughly 50-year period when:
almost no sunspots occurred on the Sun
143
Helium fuses to produce
carbon
144
What is the process by which helium fuses in low mass stars?
triple alpha process
145
When helium fusion begins in the core of a red giant star, the situation quickly gets out of control because electrondegeneracy pressure does not respond to changes in:
temperature
146
The core of low-mass stars end their life as a
White dwarf
147
A nova is the result of which explosive situation?
Mass transfer onto a white dwarf
148
A Type Ia supernova occurs when a white dwarf reaches a mass of __________.
1.4 Msun
149
The relation between pulsation period of a Cepheid variable star and its luminosity allows us to determine its:
distance
150
An iron core cannot support a massive main-sequence star because:
iron cannot fuse with other nuclei to produce energy
151
What is the minimum mass main-sequence star that can become a Type II supernova?
8 Msun
152
Essentially all the elements heavier than iron in our galaxy were formed:
by super novae
153
Neutron stars have masses that range from:
1.4 Msun to 3 Msun
154
If astronauts travel at 60,000mph to and from Mars over the course of a year (by their clock), people back on Earth
should measure _________ to have passed.
very slightly more then one year
155
__________ is the result of mass distorting the geometry of space-time
Gravity
156
Black holes form from the collapse of stars with cores greater than:
3.0 Msun
157
When extremely massive stars collapse, all of their remaining mass is
compacted to a dimensionless object called a singularity
158
The event horizon of a black hole is defined as:
the radius at which the escape speed equals the speed of light
159
A colleague near (but outside) the event horizon of a black hole signals you using a blue laser. What would you see?
Their signals, but shifted to a longer wavelength (redshift) because they are very close to a massive object
160
What makes up the majority of the mass of an individual spiral galaxy?
Dark matter
161
Supermassive black holes are found
at the center of every galaxy
162
21-cm radiation is important because:
it allows us to image neutral hydrogen in the interstellar medium
163
Sagittarius A*, the radio source located at the center of our galaxy, is believed to be:
a supermassive black hole
164
The Local Group consists of
the Milky Way, Andromeda, Triangulum, and several dwarf galaxies
