Quiz 2 Flashcards
(133 cards)
1
Q
Exploration of Mercury
A
- 3 space craft
- boring dull
- political/ social reasons for not a lot of exploration
2
Q
Exploration of Venus
A
- 40+ spacecrafts gone/ mostly Russia
- easy to get to
- cloud cover is/mysterious
- lander, orbiters, and balloons have been
- activity in 60s and 70s
- not a lot after collapse of USSR
3
Q
Exploration of the Moon
A
- lots of activity when learning how to shoot rockets but became boring
- now wanting to be moon base, mining, for man
4
Q
Exploration of Mars
A
- lots of activity in 60-70s
- lull in 80-90s
- lots of activity now
- many missions
5
Q
Exploration of Asteroids
A
- none before 1989
- public does not care
- small with no gravity, hard to land on or explore
6
Q
Exploration of Jupiter
A
- 7 all American missions
- could not use solar panels as power
- so they used nuclear reactors, small and expensive
7
Q
Exploration of Saturn
A
- 4 all American missions
- far away and 1000x the size of earth
8
Q
Exploration of Comets
A
-none before 1985 because the move faster with very little gravity
9
Q
Accession Disc Theory
A
- solar nebula theory
- as gas/dust collapses, pieces “acret”
- bump into each other and stick and grow into planets
10
Q
Evidence of accession disc theory
A
- other stars have discs around them
- we should see planets around other stars
- stars should wiggle from pull of planets
11
Q
Astrometry
A
- track movement of stars relative to background
- we tracked stars for decades
- didn’t find any
12
Q
“first” extra solar planet found
A
- found around dead exploded star
- but he found earth and was embaressed
13
Q
actual first extra solar planet found
A
- we didn’t find it at first because awe assumed planets had orbits like those in our solar system
- found around another regular star
- assumed to be an error
- it has 4 day revolution
- found by mayor and Pegg
- called 51 Pegg
14
Q
Lessons in Extra-solar Planet Discovery
A
1) theory must be validated by observation or experiment
2) Human bias is hard to overcome
3) verify results before publishing
4) your results build on other results
5) discoveries are often very unexpected
15
Q
new technique to find planets
A
looking for light shifts due to sun passing in front of planets. vice versa
16
Q
two types of planets
A
terrestrial, jovian
17
Q
Terrestrial Planets
A
- small
- rocky/dense
- inner solar system
- few moons
- no rings
18
Q
Jovian planets
A
- larger
- gaseous/low density
- outer solar system
- lots of moons
- all have rings
19
Q
what things in space have craters on them
A
every hard surface
20
Q
non planet objects
A
- asteroids
- meteors
- comets
21
Q
Asteroids
A
small rocky orbit between mars and Jupiter
22
Q
Comets
A
icy with elliptical orbits, tails near sun
23
Q
Meteoroids
A
tiny rocks often burn up in earths atmosphere
24
Q
accession disc theory implies that
A
everything is the same age
25
what is the best method to determine age
radioactive dating
26
what is radioactive dating
- looking at molecules because they emit a particle
| - approximate time for decay is half-life
27
half-life
time for half of all particles to decay by measuring the percent that decay
28
what is often used to date objects younger that 50,000 years
C14
29
how old are moon rocks
4.5 billion years old
30
how old are meteorites
4.6 billion years old
31
how old is earth
3.9 billion years old
32
how old is mars
4.3 billion years old
33
how can accession disc theory be right if the things are all different ages
you have to account for the time it takes for things to cool
34
evidence to solar system formation
1) disc shape
2) orbits in same direction
3) two planetary types
4) rings around Jovian planets
5) craters everywhere
6) space debris
7) all things about same age
35
what is the sun made up of
73% hydrogen, 25% helium, 2% heavy elements
36
based on solar nebula theory what should planets be made of
98% hydrogen and helium
37
why is earth not made of 98% hydrogen and helium
- early earth was
- little planets could not hold it all due to weak gravity
- big planets lost some but still have lots of He, H
38
what does solar wind do
strips away upper layer of terrestrial atmosphere
39
accretion
- many small grains collide and stick
| - speed dependent
40
condensation
gases collide with grains and condenses
41
Planetsimal
due to condensation and accretion, small rocks become bigger about centimeter in size
42
protoplanet
when rocks accret and become at least 100km in size
43
protoplanets grow slowly or quickly
quickly because they steal food from other planets
44
two tories about how protoplanets become planets
homogeneous accretion and heterogenous accretion
45
homogenous accretion
- similar type planetsimals merge
| - heat makes them liquid
46
heterogeneous accretion
- iron planetesimals form first and merge to create a core
| - then other types of planetismals collide to form outer layers
47
when does plant growth start to slow down?
when sun ignites and solar wind blows away remaining dust and gas and leaves behind rocks and planets
48
we observe craters on what kind of surfaces?
all solid ones and is strong evidence of accretion disc theory
49
what is the theory of how planets were created
planets developed from gas and dust via condensation into grains, growth by collision, then by gravity into planets
50
why are solid/ terrestrial planets in the inner solar system
because its warmer and only heavy elements condense into grains
51
why are jovians in the outer solar system
because icy lighter elements also condense far away
52
why should jovian be larger
because they have more "food" at larger distances
53
what can jovian do that terrestrials can not
trap H, He atmospheres
54
why do jovian have more moons
because their larger and their gravity is capable of trapping moons
55
why are there rings around jovian planets
because there is less solar wind out there
56
what are left over planetesimals and protoplanets
comets, asteroids, and meteors
57
meteors
in the air/ atmosphere
58
meteorites
on the ground
59
meteoroids
in space
60
what are meteors made of
rock, dust, ice, is a small asteriod
61
when do you see meteors the best?
in the morning
62
what is a meteor shower
swarms of meteors
63
do meteors all go different ways
no, despite appearance, they all move in the same direction
64
what are the three types of meteorites
iron, stoney, and stony-iron
65
do we find more iron or stoney meteorites and why
iron because they stand out and they fall apart slowly
66
where do most asteroids orbit?
around mars and Jupiter
67
what is the largest asteroid we know of
Ceros
68
why type of asteroids have earth crossing orbits
Apollo asteroids
69
what is the theory for the asteroid belt
protoplanets that never formed a planet
70
what are the tree types of asteroids
S- bright, reddish, inner solar system
C- dark, outer solar system
M- bright not red
71
what plays a roll in the type of asteroid
the environment
72
what are two random facts about asteroids
- evidence of volcanism
| - they are very old
73
comet Halley
- 17.8 AU
- elliptical
- retrograde
- takes 100 years to orbit the sun
74
dirt snowball theory
comets have dust mixed in with ice and over time they develop a crust
75
how is the tail of a comet made
when they get close to the sun, the ice turns into gas and escapes through a small hole and gets blown outward by solar wind
76
two types on comet tails
Gas tail and dust tail
77
Gas tail
ionized, flow with magnetic field
78
Dust tail
dust, flows with solar wind
79
what is the structure of a comet
very low density (fluffy snowbanks) loosely held together and often break apart
80
Oort cloud
- giant cloud of comets in outer solar system
| - sometimes stars will knock some into the inner solar system
81
What does the accretion disc theory imply
- that a rock hit earth
| - we still see rocks and ice balls
82
what would be the consequence of a large impact
- tidal waves
- dust covering earth causing plants/ animals to die
- earthquakes
- volcanos
- shock wave
- heat wave causing fires due to friction
- ejecta landing elsewhere
- panic, looting, religion
- communications fail from satellites
83
I comet would cause multiple impacts
true
84
what planet has been recently hit by comet
Jupiter
85
how were dinosaurs wiped out? and what theory does it support
an impact and supports accretion disc theory
86
why WAS the common theory until 1979 about how dinosaurs died
by climate change
87
how can we support the idea that a comet killed dinosaurs
because we found a crater with traces of iridium (an element commonly found on on asteroids
88
for every major impact there should be what
many other smaller impacts
89
in what biblical reference showed evidence of accretion disc theory
sodom and Gomorra
90
what was the Tunguska event 1908
- ball of flames
- trees were found flattened radially
- dust/fires/explosion witnessed
- no meteorites found
91
what was the Brazil event 1930
- explosion In sky
- forrest fire
- people thought world was ending
- smaller
92
what was the Chicago fire event
- said to be "miss O'leary's cow" that kicked over a lamp
- same night there were dozens of fires in 4 states
- worst fire in US history
- trees flattened
93
what was the event in Russia
- 1200 injured in Russia
- bright flash, heat wave, vapor trail, glass
- 50 feet meteor
94
after earth was formed what happened
it went through a slower evolution with weathering, planets, and continental drift
95
what cause earthquakes and seismic waves
movement in the crust
96
what is the order of earths layers
crust, mantel, outer core, inner core
97
what structure does the mantel have
is rock but flexible like asphalt
98
how thick is earth crust
40 miles thick under continents and 6 miles thick under oceans
99
what is the relationship between the crust and mantel
- crust is low density and sits on the mantel like foam on a beer
- convection in the mantel pushes crust around
- crust is recycled with new material rising
100
plate techtonics
crustal movement
101
what evidence shows that continents were once together
fossils, scratches from glaciers on India, see same kid of rock
102
how did the Appalachians form
when Africa hit north America 200 million years ago
103
what is the dynamo theory
- motions of iron in the liquid core generate earths magnetic field
- not much confidence in this theory
104
what is the mystery about earths magnetic field
it reverses randomly throughout history
105
what creates auroras
-solar wind particles penetrate magnetic field at poles
106
what was the first atmosphere of earth
- the primeval atmosphere
| - probably rich in NH3, CH4, H, He
107
what was earths secondary atmosphere
- rapidly evolved and He, H floated away
- sunlight broke apart NH3 and CH4
- leaving only N and C
108
what do we think the source of our oceans were
lots of comets that hit earth and melted, leaving H2O
109
what was earths third atmosphere like
- developed as CO2 and became o2/rock
- because of planets
- oceans turned CO2 into rock
110
snowball theory
- proposes that O2 levels jumped from O to 1% and then to 20%
- ice caps cover the earth
111
what is earths atmosphere like
- man is changing the air pollution
| - global warming ?
112
greenhouse gases
- gas that is transparent to solar radiation but opaque to inferred
- carbon dioxide and methane
113
what greenhouse gas helps keep earth warm
CO2
114
how is CH4 increasing
cows and rice
115
what is the #1 greenhouse gas
water H2O
116
why was Columbus blamed for "Little Ice age"
- he ultimately killed 90% of native Americans when he discovered America
- didn't have anyone to feed so more trees grew on top of old farm land
- took all CO2 from air and dropped earths temperature
117
is Antarctica loosing ice mass?
- no, snowfall would increase with warmer earth
| - but, at edges ice loss is going up
118
what happens to the ocean if earth warms
sea levels would rise because water expands when its heated
119
what is an investing theory about a warmer earth
- as temp goes up, sea levels go up, this causes temp to go down
- because this increases volcanism
- thus, dust in the air
- maybe causing earth to cool more
120
what other planet has acid rain
venus
121
our clouds vs other planets clouds
ours are H2O but they could also be other molecules on other planets
122
what is the cause of the ozone hole
C4C's cause chemical reaction leaving a hole in the atmosphere
123
tides on earth vs moon
- not only does the moon cause tides on earth but earth cases tides on the moon
- land tides
124
what would happen if moons rotation did not equal its revolution
the tide would be off set
125
today forces do what to the moon
- slow down its rotation
| - over the years moons rotation has slowed to match its revolution
126
does moon have an atmosphere
no
127
what are Mares on the moon
lava field with a few centimeters of dust
128
what do moons craters tell us
- number of craters tells us how old the area is
| - crater counting theory
129
which is younger: the mare or highlands
the Mare
130
how is a crater formed
- impact causes surface to melt and then refeeze
- central peaks form
- crater rims form
- created like a drop of milk
131
what are some things we see or have seen on the moon
- volcanos were present millions of years ago but now the crust is too thick
- we see "rivers" of lava
132
what are rilles
- a Vally or trench on the face of the moon
- caused by faulting due to big impacts not plate tectonics
- much like a rock hitting a mirror
133
are there plate tectonics on the moon
no, because the crust is way too thick
