Final Flashcards
(423 cards)
1
Q
The study of the moon is called
A
Selenologists
2
Q
Most places on earth experience ____ high ___ and ___ low ___
A
two high tides & two low tides
3
Q
Tides are created mainly by the influence of this celestial object:
A
moon
4
Q
The ___ also causes earth’s tides, but it only has about ___ the effect of the moon.
A
sun; 1/2
5
Q
When the moon is full or new, we experience ___ tides.
A
Spring
6
Q
When the moon is at quadrature (1st or 3rd Quarters), we experience ___ tides
A
Neap
7
Q
___ tides are the most exaggerated tides (really high high tides and really low low tides)
A
Spring
8
Q
We have ___ tides and ___ tides each month
A
Spring; Neap
9
Q
Explorer 1 discovered these belts of trapped, electromagnetically-charged particles:
A
Van Allen Belts
10
Q
The moon’s crust, like other terrestrial bodies, is made of these two rocks:
A
granite & basalt
11
Q
3 principal layers of a terrestrial planet or moon:
A
crust, mantle & core
12
Q
The Earth’s core is principally made of these metals:
A
magnesium & iron
13
Q
The arrangement of materials from densest at the core to least dense outward, is caused by this process:
A
chemical differentiation
14
Q
Lunar maria are made principally of this rock type:
A
dark basalt
15
Q
How is lunar far side different from its nearside?
A
Twice as thick crust
16
Q
Why is the lunar far side different from its nearside?
A
Long axis aligned with Earth’s gravitational pull
17
Q
This process is responsible for the movement of Earth’s surface features:
A
plate techtonics
18
Q
The margins of tectonic plates are places where these occur:
A
earthquakes & volcanoes
19
Q
Over 200 million years ago, this “supercontinent” existed:
A
Pangea
20
Q
This plate boundary, such as in the mid-Atlantic Ocean, is where new crust is being made:
A
Divergent (Iceland)
21
Q
This plate boundary, such as at Indian and Nepal, is where continental crust collides:
A
Convergent (Himalayas)
22
Q
This plate boundary, such as at San Andreas, is where two plates run past each other:
A
strike-slip
23
Q
Geologically speaking, the moon is:
A
dead
24
Q
Scientific name for lunar soil:
A
regolith
25
If the moon has no volcanic activity or moonquakes or atmosphere, where does the regolith come from?
micrometeriorites from Earth's atmosphere
26
All of the planets revolve in this direction:
counterclockwise
27
A planet's rotational speed is directly related to its distance from the sun: T/F
False
28
The order of the planets outward from the sun:
rocky inner, gas giants outer
29
What are the two classes of planets?
Jovians (gas giants) & Terrestrials (rocky planets)
30
Terrestrials are found in the ___ solar system
inner
31
Jovians are found in the ____ solar system
outer
32
Largest planet in the solar system:
Jupiter
33
2nd largest planet in the solar system:
Saturn
34
The jovian planet's main constituents:
hydrogen, helium, methane, ammonia
35
Largest terrestrial planet:
Earth
36
2nd largest terrestrial planet:
Venus
37
3rd largest terrestrial planet:
Mercury
38
Liquid water is found only on this planet:
Earth
39
The number of sunspots in the solar photosphere reaches a peak every ___ years
11
40
The suns's visible surface:
photosphere
41
Large dark spots in the suns photosphere:
sunspots
42
Sunspots are dark because they're ___ than the surrounding solar photosphere.
cooler
43
Photosphere temperature:
11,000 degrees
44
Sunspot parts - cooler, inner ___; slightly warmer, out ___
umbrea; penumbra
45
Sunspots are permanent features: T/F
false
46
Great glowing jets or clouds of gas int he solar chromosphere:
prominences
47
Outermost layer of the sun containing superheated plasma:
chromosphere
48
Large, powerful sunspots can often release these vast explosion eruptions:
flares
49
Subatomic particles ride the ___, creating ___ in Earth's atmosphere
solar wind; aurora
50
Three early ideas of how the sun made energy:
chemical burning; gravitational contraction; bombardment by asteroids
51
___ devised the absolute magnitude scale, where 0 degrees - the point where all molecular activity stops
Williams Thompson (Lord Kelvin)
52
"Heat flows from a hotter body to a colder one" is the ___ of thermodynamics.
2nd
53
Besides the Kelvin scale, what are two other commonly used temperature scales:
fahrenheit & celsius
54
Convert to Fahrenheit: 0 degrees Celsius
32 degrees (freezes)
55
Convert to Fahrenheit: 100 degrees Celsius
212 degrees (boils)
56
Convert to Fahrenheit: 0 degrees Kelvin
-459 (molecular activity presumably stops)
57
Why weren't geologists okay with Kelvin's 30 million year estimate for the sun's age?
Earth was estimated to several hundred million years old
58
___ devised the laws of special and general relativity.
Albert Einstein
59
This formula explains how matter is converted into energy, is the secret of the sun's success:
E=MC2
60
In E=MC2, E = ___
energy produced
61
In E=MC2, M = ___
mass detroyed
62
In E=MC2, C = ___
speed of light
63
Temperature of the solar core:
27 million degrees
64
In the solar core, hydrogen is converted into ___
helium plus energy
65
The process fo splitting heavy elements into smaller units is nuclear ___
fusion
66
The combining of light elements into heavier ones is nuclear ___
fission
67
The sun's nuclear fusion process, whereby hydrogen atoms combine to ultimately form helium and energy is called the ___
proton-proton chain
68
In more massive stars, the nuclear fusion process is called the ___
carbon cycle
69
The sun's gravity field is so powerful that it can ___ light
bend
70
In 1919, during a ___, the deflection of starlight by the sun's gravity field was first detected by Sir Arthur Eddington
total solar eclipse
71
These "wrinkle" in the Mercurian crust are the result of shrinkage of the planet:
lobate scarps
72
Impact feature on Mercury, over a thousand miles across:
caloris basin
73
This spacecraft once orbited Mercury, but it recently smashed into it:
Mercury Messenger
74
Compared to its crust and mantle, Mercury's metal core is comparatively:
large
75
The atmosphere of Mercury is ___
non-existent
76
Venus' atmosphere is made of:
carbon dioxide
77
Our sister planet:
Venus
78
The air pressure eon Venus is ___ that of Earth's
90 times
79
The surface temperature on Venus:
900 degrees Fahrenheit
80
This effect has caused Venus' atmosphere to become superheated:
greenhouse effect
81
With coronae and volcanoes and tectonics, geologically speaking, Venus is ___
active
82
Impact craters on Venus are not generally very big or very small, but mostly ___
mid-size
83
Mars is ___ the size of Earth
1/3-1/2
84
Mars rotation rate compared to Earth's:
24 1/2 (slightly longer)
85
Mars has these cold polar features that grow and shrink with the seasons:
ice caps
86
Mars ice caps are made up of both water ice and ___
dry ice
87
In 1887, a ___ brought us within 35 million miles of ___
perihelic opposition; Mars
88
At the U.S. Naval Observatory, ___ found Mars' two small moons.
large 26" refractor
89
Mars two small moons:
Phobos; Deimos
90
___ observed canali (channels) on Mars; the wod was mistranslated as ___.
Giovanni Schiaparelli; canals
91
He advanced the idea of intelligent Martians who built irrigation canals:
Percival Lowel
92
15 mile high volcano on Mars:
Olympus Mons
93
3000 mile long crack in the ground on Mars:
Valles Marineris
94
Dry river valleys, flood zones, alluvial fans and sea or lakebed, as well as hematite "blueberries" on the Meridian plains are a good indicator of ___ in the past on Mars.
liquid water
95
Gaspra, Ida, Mathilde and Eros are all examples of these:
Asteroids
96
Another name for an asteroid:
minor asteroids
97
He found the first asteroid telescopically, and named it Ceres:
Father Guiseppi Piazzi
98
___ Law is a numerical sequence which suggested the existence of the ___ as well as planets beyond the orbit of Uranus
Bode's; asteroids
99
Bode's Law is not a law because its is not ___ and it doesn't always ___
universal; work
100
A popular scientific theory suggests that the dinosaurs were killed off by ___
meteors
101
A streak of light in the night sky is called a ___
meteroid
102
The rock in outer space prior to its burning up in the Earths atmosphere is called a ___
meteor
103
When a meteor hits Earth, it's call a ___
meteorite
104
A bright meteor is known as a ___
fireball
105
If a meteor loudly explodes, it's called a ___
bolide
106
Characteristics of meteorites:
heavy, magnetic, with fusion crust
107
This type of meteorite is metallic and readily identifiable as meteoritic in nature:
iron-nickel
108
Iron meteorites, cut, polished and etched, reveal these iron crystals:
widmanstatten pattern
109
These meteorites are made of stony materials, like earth rocks:
achondrites
110
These stony meteorites contain rounded bits of glassy rock:
chondrites
111
This meteorite type is a mixture of stony and iron
tektites
112
Jupiter is 1/2 billion miles from the sun, Saturn is 1 billion miles from the sun, Uranus is ___ billions miles from the sun
2
113
Because of its fast rotation and resulting centrifugal force, the planet Jupiter is wider at the equator than from pole to pole, making it ___
oblate
114
Large hurricane on Jupiter, 2-3x the size of Earth, w/ 400 mph winds:
Great Red Spot (GRS)
115
The GRS has been observed telescopically for ___ years
400
116
These atmospheric phenomena are to be found at Jupiter:
storms, lighting, and aurorae
117
This comet smashed into Jupiter in 1994:
Shoemaker-Levy 9
118
Jupiter's outer moon - ancient, heavily cratered terrain:
Callisto
119
Largest moon in solar system (Jupiter) featuring ice, grooved terrain:
Garymede
120
Fresh, smooth-surface moon of Jupiter with fine cracks in icy crust and subsurface water:
Europa
121
Tidally heated, sulfur covered Jupiter moon with many active volcanoes:
Io
122
Which of the gas giant planets has rings:
Jupiter, Saturn, Neptune, Uranus
123
Volume of space controlled by a planet's magnetic field:
magnetosphere
124
What are Saturn's rings mainly made of:
tiny water ice chunks
125
Saturn's density is less than:
water
126
Besides the ___ gap, there is also ___ division in Saturn's rings
cassini; enke
127
Electrostatically charged dust suspended above Saturn's rings:
spokes
128
Titan possess a thick atmosphere made principally of this gas:
nitrogen
129
This musician discovered the planet Uranus (almost named, "George") in 1781:
William Herschel
130
What may have caused Uranus' sideways tilt?
Collision, or planets may tip time to time
131
Of Uranus' dozens of moons, this one has ice cliffs several miles high:
Miranda
132
This Earth-sized Neptunian feature has recently disappeared:
The great dark spot
133
This Neptunian moon orbits backwards or retrograde
Triton
134
These eruptive features are found on Triton:
Cryovolcanoes
135
Besides promoting Martian canals, Lowell postulated a ninth planet known at the time as ___
Planet X
136
Planet X was discovered in 1930 by ___
Clyde Tombaugh
137
Tombaugh discovered the planet one night while looking through a telescope: T/F
False
138
Planet X was soon named:
Pluto
139
Because Pluto's orbit is more elliptical and offset from the others, it sometimes slips inside ___ orbit.
Neptunes
140
Besides Charon, Pluto has four more moons discovered only recently;
Nix, Hydra, Styx and Kerberos
141
The amount of reflectivity of a planet:
albedo
142
Kuiper belt objects such as Quaor, Sedna and Eris are classified as ___
ice dwarfs
143
Short-period comets may come from this belt outside Neptune's orbit:
Kuiper belt
144
This spherical cloud of comets surrounds our solar system:
Oort Cloud
145
In 1682 he saw the comet that would later be named for him:
Edmund Halley
146
Haley thought that the comets did not travel in straight lines, but instead had ___
elliptical orbits
147
The orbits of many comets are highly ___
elliptical
148
Recent apparitions of Halley's Comet:
1682, 1759, 1835, 1920 (142 years)
149
Halley's Comet reappears in:
2052
150
Comet Hale-Bopp is a good example of a ___ period comet
long
151
Halley's comet is a ___ period comet
short
152
Comet tails always point ___ from the sun due to the pressure of solar radiation and flow of subatomic particles outward - the solar wind.
away
153
Parts of a comet: the atmospheric head, called a ___
Coma
154
Parts of a comet: the dust and gas blown off the coma by the solar wind:
tail
155
The ___ tail of a comet extends out in a straight line
iron or gas
156
The ___ tail curves away from a comet in an arc
dust
157
Spacecraft have flown past comet tails, struck comets, and brought back comet tail material to Earth: T/F
True
158
The dense worlds are found in the ___ solar system
inner
159
The gas giants are located in the ___ solar system
outer
160
This kind of material boils at fairly low temperatures:
volatile
161
This kind of material remains solid at high temperatures:
refractory
162
This hypothesis best explains the moon's origin:
large impact theory
163
The ___ suggested that a passing star pulled material from the sun to form planets
planetismal theory
164
The ___ suggested that hot gas blew off the sun to form planets
tidal theory
165
The ___ suggested the sun was a binary, but the companion blew up making planets.
double star theory
166
The ___ was the basis for our modern ___; suggesting that the sun and planets formed from a cloud created by exploding stars
condensation theory; solar nebula
167
According to the solar nebula theory, the solar system began about ___ billion years ago
4.6
168
How was this age determined? (universe)
Radioactive dating of meteorites
169
Large planet-building objects that formed from the solar nebula:
planetesimals
170
Massive objects destined to become planets:
protoplanets
171
If the solar nebula theory is right, then planets should be very ___ in the Universe.
common
172
Visual evidence of solar nebulae has been found as protoplanetary discs, or ___ in the ___ and in the spectroscopic wobbles or nearby ___.
proplyds; Great Orion Nebula; Stars Spectra
173
The speed of light, symbolized by the letter C, is approximately 186,000 miles per second. Given that there are roughly 33 million seconds in a year (60 X 60 X 24 X 365.25), light can travel about ____in one year.
6 trillion miles
174
The speed light can travel in one year:
lightyear
175
A "parallax second of arc," is called a ___
parsac
176
A parsec is equal to about ___ light years
3.26
177
Objects beyond our solar system, such as stars, nebulae, and galaxies:
deep sky objects / deep space objects
178
All of the stars we can see with the naked eye are part of the ___
Milky Way Galaxy
179
This French astronomer made a list of a hundred or so fuzzy objects that weren't comets:
Charles Messier
180
When comets are far from the sun, they don't have ___
tails
181
One way to determine if a fuzzy object is a comet is to see if it ___ against the background of stars.
moves
182
The first Messier object, M-1, is really the ___ nebula, the exploded remains of a star
crab
183
The Messier list objects comprise of ___ star clusters & ___ star clusters
nebula, open; globular
184
At 4.3 LY, the nearest star to us after the sun (so far as we know):
Alpha Centauri (Rigel)
185
of stars in the Alpha Centauri system
3
186
Common center of mass in the Alpha Centauri system:
barycenter
187
Of the three stars of Alpha Centrauri, this red dwarf is the closest to us:
Proxima
188
The most common kind of star:
red dwarf
189
The rarest kind of star:
blue giant
190
Stars are formed from the contraction and heating up of ___
nebulae
191
Our sun is sometimes designated as a ___
yellow dwarf
192
Barnard's Star and Proxima Centauri are ___
red dwarfs
193
The stars we see in the sky at night are predominately the most common - red dwarfs: T/F
False - too faint to see
194
Betelgeuse, Aldebaran and Antares are very bright but also very ___
cool
195
Stars: ___ and ___ giants
red; blue
196
Stars:___ and ___ dwarfs
white; red
197
Stars: ___ stars and ___ holes
neutron; black
198
Massive stars that blow up:
supernovas
199
Blue giant characteristics:
massive, hot, bright (Rigel, Vega)
200
Red giant characteristics:
big, cool (Betelgeuse, Antares, Aldebaran)
201
White dwarf characteristics:
small, hot (Sirius B, Procyon B)
202
Neutron stars are also called ___
pulsars
203
Pulsar star characteristics:
small, very hot, dense, magnetic, rotate rapidly
204
There is a neutron star in this nebula:
crab
205
___ is a good example of a black hole, but it was not discovered until the 1960's
Cygnus X-1
206
Two basic kinds of star cluster: ___ and ___
open; globular
207
Open star clusters are also called ___
galactic star clusters
208
Two examples of open star clusters: ___ and ___
Pleiades; Praesepe
209
___ star clusters are spherical in shape
Globular
210
Globular star clusters contain ___ of stars, and they are ___
millions; very, very old
211
Two examples of globular star clusters: ___ and ___
M13 Hercules, Omega Centauri
212
A large cloud in outer space: ___ and ___
nebula; nebulae
213
Nebulae are composed of ___ and ___ and are trillions of miles across.
gas; dust
214
A ___ is mainly dust with very little gas, like the nebulosity around the Pleiades
reflection nebula
215
A ___, aka a Barnard cloud or Bok globule, has no bright stars within to light it up
dark nebula
216
An ___ is the birthplace of new stars; the gas is lit up by the light of stars within.
emission nebula
217
Examples of emission nebulae:
Lagoon, Eagle, Trifid, Rosette, N. American
218
A ___ is the listed-off outer atmosphere of a dying star.
planetary nebula
219
Examples of planetary nebulae:
Hourglass, Eskimo, Ring, Dumbell, Catseye, Spirograph, Helix
220
A ___ nebula is not really a nebula, but a distant galaxy, like the ___ galaxy
spiral; Andromeda
221
A star's ___ tells us its temperature
color
222
Cool stars are ___
red
223
Hot stars are ___
blue
224
Newton used a prism to split the sun's light into its component colors, a ___ spectrum
rainbow
225
The colors of a rainbow spectrum, as noted by Newton
red, orange, yellow, green, blue, indigo, violet
226
The light that the human eye can see is called ___
visible light
227
The prism separates the colors of visible light by ___ its different wavelengths to various degrees
bending
228
A rainbow fringe around an image produced by a lens is called ___
chromatic aberration
229
A complete collection of colors caused by splitting light
continuous spectrum
230
Name the full spectrum of light from lowest to highest energy:
radio, infrared, visible, ultraviolet, x-ray, gamma ray
231
A device that allows us to see absorption lines in a spectrum of light:
spectroscope
232
Dark absorption or Fraunhofer lines make up this kind of spectrum:
absorption spectrum
233
An absorption spectrum is caused by ___ absorbing select wavelengths of light
cool gasses
234
Bunsen and Kirchoff discovered this kind of visible light spectrum:
emission (bright light)
235
An emission spectrum is made by causing a low-density ___ to glow and emit select wavelengths of light
nebula
236
Each element has its own spectral ___ allowing us to identify the compositions of stars.
signature
237
Modern spectral analysis is accomplished not with prisms but with ___
diffraction gradings
238
This effect causes blue shifts and red shifts in stars ___
doppler
239
A higher frequency of light represents a ___ shift
blue
240
A lower frequency of light represents a ___ shift
red
241
The star Spica has red-shifted spectral lines; six months later its lines are blue-shifter. What causes this?
Earth revolution carries us towards and then away
242
Kind of velocity exhibited by red or blue-shifted stars:
radial
243
The greater the Doppler shift , the ___ the radial velocity of the object
greater
244
Faint stars without Arabic names, greek or Roman letter designations, have ___
Flamsteed numbers
245
He was England's first royal astronomer and built the Greenwich Observatory:
John Flamsteed
246
This Danish astronomer was first to determine the speed of light:
Ole Roemer
247
The small shift in a star's position caused by viewing it from two different locations:
stellar parallax
248
Given D=1/p, calculate the distance to Alpha Centauri if its parallax is .75 arc second
Divide 1.00 by .75 = 1.33 pc
249
After parallax has been taken into account, stars that change their positions among the other stars over time display what's called:
proper motion
250
Two stars that orbit each other are called ____
binary stars
251
A binary where the stars are far enough from each other that the telescope can let you see them visually is called a ___
visual binary
252
At first glance, they look like a binary star, but they're not actually bound gravitationally:
optical double
253
It looks like one star, but its spectral lines periodically split and then re-merge, the split again:
spectroscopic binary
254
A binary system where two stars pass in front of each other:
eclipsing binary
255
This star in Perseus is an eclipsing binary system:
Algol
256
The ___ of eclipsing binaries allows us to measure their orbits and velocities, their diameters and their masses and sometimes their share and surface features.
light curve
257
When a cool star eclipses a hot star, the system's brightness drops ___ than when a hot star eclipses a cool one
a lot more
258
___ devised the spectral classes of stars
Annie Cannon
259
Spectral classes of stars from hot to cool:
O, B, A, F, G, K, M
260
Make up a mnemonic to remember the order:
Oh boy, a fat gorilla kicked me
261
Each spectral class of star is further subdivided into ___ classes
10
262
The ___ law applies to the way light dims with distance.
inverse square
263
If Jupiter is 500 million miles from the sun and Uranus is 2 billion miles out, how much less light does Uranus get than Jupiter
1/16
264
If star A and star B are the same size and the same temperature, but star B is three times farther away that star A, how much dimmer does star B appear than star A
9 times
265
If star A and star B are the same distance away, but star B is much fainter than star A, then star B's absolute magnitude is much less than star A's.
True
266
If star A and star B are the same size and temperature, but star A appears 100 times brighter than star B, then star A must be ___
10 times closer
267
The true measurement of a star's visual brightness:
absolute magnitude
268
___ and ___ devised the Hertzsprung-Russel diagram
Hertzrung; Russell
269
The HR diagram plots a star's ___ or ___ against its ___ or ___
temperature, spectral class; absolute magnitude, luminosity
270
The ___ of a star compares its brightness to that of the suns
luminosity
271
The absolute magnitude of a star is its apparent magnitude if it were ___ away from us.
10pc
272
At a distance of 10 pc, the sun's apparent magnitude would be ___
5th Mv
273
___ stars have a red color
M
274
___ stars are orange
K
275
___ stars are yellow
G
276
___ stars are blue / white
O&B
277
In the HR diagram, hot stars are on the ___ side
left
278
In the HR diagram, cool stars are on the ___ side
right
279
In the HR diagram, bright stars are at the ___
top
280
In the HR diagram, dim stars are at the ___
bottom
281
90% of all known stars fall along this line on the HR diagram:
main sequence line
282
As you go up the main HR sequence, the star temperatures and brightness ___
increase
283
Cool dim stars:
red dwarf
284
hot, bright stars:
blue giants
285
cool, bright stars:
red giants
286
hot, dim stars
white dwarfs
287
Red giants and white dwarfs are off the main sequence: T/F
True
288
Stars are formed out of emission-___
nebulae
289
When the hydrogen in the core of a star is used up, the star begins to ___
die
290
The less massive the star, the ___ it lives
longer
291
The more massive the star, the ___ its lifespan
shorter
292
___ have such long lives that some of them started glowing when the universe was young
Red dwarfs
293
Our own sun has shone for ___
5 billion years
294
Our own sun will shine for another ___
5 billion years
295
The only star that typically never becomes a red giant is a ___
red dwarf
296
When the sun finally dies, it will explode as a supernova, then collapse to become a black hole: T/F
False
297
When the sun's nuclear furnace shuts down, it will first ___; then ___ will begin to "burn" in a shell surrounding the solar core. About this same time, ___ will begin to burn in the core, making ___. The sun will then ___ and become a ___ giant.
contract & heat up; hydrogen; carbon; helium; swell; red
298
When the outer atmosphere of the sun "lifts off" and expands out into space it will make a ___
planetary nebula
299
Eventually the sun will burn up its shell hydrogen and core helium and collapse to become a ___
white dwarf
300
When the sun becomes a white dwarf, it will be the size of ___
Earth
301
A long time after the sun becomes a white dwarf, it will cool to become a ___
black dwarf
302
___ are exploding stars
Supernova
303
The last nearby supernova seen occurred in ___ in the ___, 160,000 LY away
1987; large megellanic cloud
304
A simple ___ is a dying star, but it not an exploding star
nova
305
Novae are ___ found in ___
white dwarfs; binary systems
306
Novae pull gas from its companion down onto an ___
accretion disc
307
White dwarf stars can brighten again and again, often at regular intervals of time: T/F
True
308
If a white dwarf pulls enough material to increase its mass sufficiently, it can become a ___
supernova
309
Exploding white dwarf stars are ___ supernovae
Type 1
310
Solitary massive stars that explode are ___
Type 2
311
___ stars result from supernovae
Neutron
312
Neutron stars are about ___ across and spin ___
10 miles; fast
313
___ proposed mass limits for stars that would either become white dwarfs, neutron stars or black holes
Chandrasekhar
314
If a dying star has more than 2.4 times the mass of the sun, it will become a ___
black hole
315
At the center of the black hole is a tiny, super-dense point called a ___
singularity
316
An ___ surrounds the black hole
accretion disc
317
A black holes speed-of-light point of no return is the ___
event horizon
318
Although we can't see black holes directly, we can detect their presence due to their ___
gravity fields
319
___ can leak out from around black holes
x-rays & radiation
320
The distance from the singularity to the event horizon is known as the ___
schwarzschild radius
321
Schwarzchild radius is equal to ___ solar mass.
3km
322
if a black hole has 10 times the sun's mass, its Schwarzschild radius is ___
30km
323
Joylen =
Pulsar
324
rapidly rotating =
Pulsar
325
Hershcel's star counts led him to conclude that th eMilky Way galaxy was shaped like a ___
great disc or millstone
326
According to the Law of ___, matter is fairly evenly distributed throughout the Universe
homogeniety
327
Herschel thought we were at the ___ of the galaxy
center
328
A dark region in the Milky Way that passes through the Summer Triangle is called the ___
great rift
329
William Parsons, the Earl of Rosse, built this, the largest telescope in the world; the ___
Irish Leviathon
330
The Leviathan was powerful enough to observe individual stars in ___
other galaxies
331
Parsons suggested, as with the Whirlpool Nebula, that spiral nebulae might well be other ___
galaxies
332
___ catalogued ___ and found a connection between their absolute magnitudes and their light curve periods
Henrietta Leavitt; cepheid variable stars
333
The greater a Cepheid variable's absolute magnitude, the ___ time it takes to go through a cycle.
more
334
Using Cepheid variable stars, we can calculate their ___ even if no parallex is observable.
distances
335
Until the 1920's, astronomers weren't sure if ___ nebulae were part of our galaxy, or other galaxies beyond.
spiral
336
The Andromeda galaxy is about ___ light years, or ___ miles away
2.5 million; 15 million trillion
337
___ argued that the distribution of ___ star clusters was centered on the constellation ___; therefore, that was the center of the galaxy, not here.
Harlow Shapley; globular; Sagittarius
338
Shapley also thought the Milky Way was much ___ than most thought.
larger
339
____ argued that spiral nebulae were really distant ___
Heber Curtis; galaxies
340
Curtis cited this phenomenon, found in the spiral nebulae, to prove they were far away:
Novas
341
In 1924 Edwin Hubble cited his observation of a ___ in M31 to priove it was another galaxy
Cephid Variable
342
Three basic galaxy types:
spiral; ellipticals; irregulars
343
White spiral and elliptical galaxies can be ___ or ___, irregulars are invariably ___
small, large; much smaller
344
E0 elliptical galaxies are ___
round
345
E7 elliptical galaxies are ___
very elliptical
346
E3 elliptical galaxies are ___
in-between round and elliptical
347
Sa spiral galaxies have ___ cores and ___ wound arms
large; tight wound
348
Sc spiral galaxies have ___ cores and ___ arms
small; widely flung
349
Sb spiral galaxies are ___ Sa and Sc spiral galaxies
in-between
350
A variant of the spiral galaxy is the ___ spiral that has a bar-shaped nucleus
SBa
351
S0 spirals have a ___ shape but no discernible ___
lens/spiral; arms
352
Two small companion galaxies to the Milky Way are the Large and Small ___
Magellanic Clouds
353
While our galaxy is a spiral, the Megallanic Clouds are ___
irregular
354
Our sun is about ___ from the galaxy's center; we're in the ___ arm
2/3rds out; Orion
355
At the center of the galaxy is a ___. Surrounding it is a flattened ___; surrounding the bulge and the disc is the ___.
Nuclear bulge; disc; halo
356
The disc of a galaxy usually contains 2 or 4 ___
arms
357
The nuclear bulge and the halo are often referred to as the __
spherical component
358
The ___ is gas and dust along the band of the Milky Way that keeps us from receiving visible light from the other side of the galaxy, and beyond our line-of-sight with the disc.
zone of avoidance
359
The sun takes ___ million years to make one orbit of the galaxy; this is a ___ year
240; galactic
360
___ is a region at the center of the Milky Way, where superheated gas swirls about at fantastic speeds, driven on by a ___ with ___ million times the mass of the sun!
Sagittarius; galactic black hole; 4
361
Stars that orbit rapidly in a ___ fashion are being sped up by ___ matter in the galactic ___, which surrounds the disc and hao
non-kepleriana; dark; corona
362
Our galaxy may not be a classic spiral shape, but instead a ___
barred spiral (SBa)
363
Stars once formed in the Milky Way's ___ component, now it's mainly in the ___'s spiral arms
disc
364
There are two basic star types: ___ stars are found mainly in the disc; ___ stars are found mainly n the spherical component.
Type 1; Type 2
365
Type 1 stars have fairly ___ orbits confined to the plant of the disk
tight
366
___ stars weave in and out of the disc, often traveling at right angles to the disc stars
Type 2
367
Type 1 stars contain lots of ___ elements
heavy
368
Type II stars are ___
metal-poor
369
Type 1 stars are relatively ___
young
370
Type II stars are relatively ___
old
371
The atoms in our bodies came from:
cores of stars exploded!
372
Local group stars are ___
cluster of galaxies to which the Milky Way belongs
373
Milky Way diameter:
100,000 ly
374
Discovering of Andromeda Nebula was by ___
Hubble
375
Stars with lowest average metal content found in what part of galaxy?
Halo and Nuclear Bridge
376
Shapley thought the sun is located where?
Disc of galaxy (1/2 way out)
377
Spiral arms are found in their part of the galaxy;
disc
378
___ is detected via its gravitational exertions on other ___
Dark Matter; galaxies
379
Many large galaxies have ___ at their cores
black holes
380
Number of stars in the Milky Way:
100-200 Billion
381
M31 galaxy has ___ stars and is ___ than the Milky Way
over 300 billion; larger
382
1000 pc's is a kilo parsec, abbreviate as:
kpc
383
1,000,000 pc's is a megaparsec, abbreviated as:
mpc
384
The ___ consists of over two dozen nearby galaxies; its two largest members are the ___ galaxy and the ___
Local group; Andromeda; Milky Way
385
Most of the galaxies are this type:
elliptical
386
The Local group is a ___ galaxy cluster; Virgo, Fornax, Hercules and Coma are all ___ clusters
poor; rich
387
Superclusters of galaxies seem to be arranged in a ___ type pattern, with large ___ within them. One of the largest structures seen is the ___
soap bubble; voids; great wall
388
Galactic collisions hardly ever happen Star collisions happen frequently; T/F
False
389
The ___ (satellite galaxies of the Milky Way) have collided with us before and will eventually be absorbed by our galaxy in an act of ___
Megallanic Clouds; galactic cannibalism
390
As a result of galactic collisions and cannibalism, another class of galaxies is the ____
Active or Pecular
391
___ are active elliptical galaxies
Radio Galaxies
392
___ are active spiral galaxies
Seyfert
393
The most distant active galaxies are called ___. They are about the size of our ___
quasars; solar systemm
394
Local group diameter?
1 mpc
395
Quasars are probably the ___ of active galaxies. They are most likely powered by ___ and they are the ___ things in existence.
core; black holes; oldest
396
Quasars have very large ___ shifts
red
397
___ can produce distorted or multiple images of more distant objects. And Einstein ___ is actually one quasar whose light has been split into four images that surround the intervening galaxy.
Gravitational lenses; cross
398
___ is the branch of Astronomy that's concerned with the big questions, such as how did it all begin, where are we going, what will the Universe be like in the future.
Cosmology
399
___ pardon asks, "Why is the sky dark at night?"
Olbers
400
Thick obscuring dark clouds blocking starlight won't explain why the sky is dark because...
eventually the clouds would light up and glow brightly
401
The five assumptions in Olber's Paradox:
1: The universe is homogenous
2: Isotropic
3: Eternal
4: Infinite
5: Static
402
The fairly even distribution of stars through space is an example of the law of ___
homogeneity
403
The Universe is ___; it looks about the same no matter where you are
Isotropic
404
Which Olber's assumptions are wrong?
Universe is probably not eternal, not static
405
How is the universe not static?
It's expanding
406
If the universe is expanding, then it was once ___. ___ billion years ago, it would have all been in one place.
small; 14
407
He and Edwin Hubble convenience Einstein that the Universe was expanding; ___
LeMaitre
408
Hubble used the ___ of distant galaxies to infer that they were moving ___ from us, and that they universe was ___, which led to the ___ theory
red shifts; away; expanding; Big Bang
409
Using Hubble's Law, (D=Vr/H), and a value of H=75 km/Mpc, if a galaxy has an observed recessional velocity of 150,000 km/sec, then its distance is ___
2,000 Mpc
410
He dislike the Big Bang theory and came up with his Steady State theory instead:
Fred Hoyle
411
___% of the universe is apparently made up of ___ matter. Of the matter we can see, the composition is about ___% hydrogen and ___% helium
90-95; dark; 75; 25
412
There is no definable ___ to the Universe, therefore there is no ___ to the Universe
edge, center
413
The universe is ___ as galaxies move ___ and ___ is created
expanding; outward; new space
414
The cosmic ___ is fairly homogeneous, isotropic, and very cold
background radiation
415
Quasars move at ___% the speed of light
90
416
The farther out in space we look, the farther back in time we look - this is the phenomena of ___
look-back time
417
There are quasars nearby that formed recently: T/F
False
418
Galactic collisions were more frequent long ago, as the Universe was a smaller place: T/F
True
419
The ___ theory, no longer popular, suggests that there was no beginning and there will be no end to the Universe.
Steady State
420
The ___ theory says that everything was created out of a singularity, which expanded outward, carrying all of us with it. Evidence that supports this theory is the observed ___
Big Bang; Expansion
421
The ___ may happen in the distant future if there is enough mass in the Universe to halt the expansion and bring everything back together again - in this case, the Universe is said to be ___. In the ___ theory, another Big Bang would then occur.
Big Crunch; closed; oscillating
422
If the universe is ___ or ___, then it will not collapse back in on itself; If it is open, it will ___ forever. f it is ___ is will slow to a stop but no contract
open, flat; open; flat
423
Predicted residual heat cosmic background radiation:
George Gamov
