Post midterm ! Flashcards
(189 cards)
1
Q
Protoplanetary disk inside frostline porpotions of materials..
A
0.2 metal
0.4 rock
1.4 hydrogen compounds
98 helium
2
Q
Outside frost line porpotion of materials
A
0.2 metal (solid)
0.4 Rock (solid)
1.4 Hydrogen compounds
98 helium
3
Q
Tiny small objects stick together to form
A
planetesimals
4
Q
Planetesimals are the _____ of what will become planets
A
seeds
5
Q
How does a crater form
A
planetesimal hits surface and vaporizes rock, creating explosion
6
Q
heavy bombardment period
A
lots of planetisemals crashing everywhere after planets formed about 4 bil years ago
7
Q
mercury and moon covered in
A
craters
8
Q
LOOK UNDER SURFACE OF PLANET USING
A
SOUND WAVES
9
Q
2 types of waves (vibrational travel)
A
P waves - compression
S waves - side to side
10
Q
S wave paths
A
cant go past the liquid in the ball
11
Q
what is the empty s wave parrt that cant be reached called
A
s - wave shadow zone
12
Q
P wave paths
A
it goes through the liquid ball but everytime it goes through the curve of the line is like reflected
13
Q
Timing for seismometers at different places depend on
A
how far and fast the wave traveled
14
Q
Direction of ——– tell difference between S and P waves
A
vibrations
15
Q
S wave on graph is
A
horizontal (east to west/ north to south)
16
Q
P wave measured on graph is
A
verticle
17
Q
Mercury is estimated from
A
density + spin rate variations
18
Q
Venus is estimated from
A
density
19
Q
Earth moon mars measured with
A
seismometers
20
Q
Why do planets have cores
A
differentiation: lighter materials like rock float to top, heavier materails like iron sink
21
Q
Why planet interiors hot:
accretion:
A
Dominant during formation
22
Q
Why planet interiors hot:
differentiation:
A
more dominant earlier
23
Q
Why planet interiors hot:
radioactive decay:
A
Dominant source of heat today
24
Q
Planets cool via
A
convection
25
HOW PLANETS COOL step 1
convection:
Hot rock will rise, cool rock sink, hot rot goes surface and release heat
26
HOW PLANETS COOL step 2
Conduction:
carries the hot rock heat out cuz its thin and rigid
27
HOW PLANETS COOL step 3
radiation
energy gets radiated to space at surface as infrared light
28
smaller planets have less ------ compared to surface area of a large planet
mass
29
craters get covered by, what does it indicate
molten lava spewing out and hardening, young surface
30
are any of earths craters result from heavy bombardement
no
31
mars has 384343 craters larger than _____km
1
32
Mares on the moon are
dark spots that used to be craters but got hard lava covered it
33
Mars has many volcanoes that are
NOT ACTIVE
34
Small terrestrial planets interior cools... leading to......
rapidly
quickly ending volcanic activity
lack of volcanic activity means no outgassing cuz low gravity allows gas to escape --> no atmosphere
35
LAck of volcanic activity on small terrestrial planets means
low outgassing, so gas leaves really easily and does not form atmosphere leading to NO EROSION
36
large terrestrial size and stuff is
opposite of little planet:
Slow cooling
volcanic activity
has atmosphere?
37
outgassing produces
atmosphere
38
Temperature changes can put stress on planets crust causing. (2things)
mountains and cracksq
39
PLate tectonic workings:
Subduction at CONVERGING plates
ocean plates get pushed under continent plates, making the continental plates high (mountain)
40
PLate tectonic workings:
diverging plates
causes undersea ridges
41
No erosion likely means
water stopped flowing
42
Trend in terrestrial planet atmospheres
larger planets have thicker atmospheres
NO h2 in the atmosphere
43
Higher temperature means what for average speed
faster average speed
44
higher mass means what for avg speed
slower avg speed
45
Objects going faster than a planets escape velocity will.....
escape into space
46
lower mass planets have lower.... soo....
escape velocity, easier to escape
47
It is easier to escape a ----- planet's gravity
small
48
low mass gas moves..... so...
faster, easier to escape
49
Hot gas moves...... so.....
faster, easier to escape
50
Mercury + Moon escapes velocities are
low
51
Venus escape velocity is
high
52
Mars escape velocity is
in the middle (between mercury and venus)
53
venus, mars, merury, moon escape velocities are all
too low to keep H2
54
Carbon cycle on earth (why is N2 left as dominant gas)
Co2 in air dissolves in rainwater
water flows into ocean with minerals
Co2 in water reacts with rocks/metals to form CARBONATE ROCKS
carbonate rock is pushed to ocean floor under tectonic plates
volcanos releases small amounts of this co2 back into atmosphere
55
why doesn't earth have much CO2
it has water
56
Co2 levels on earth vary based on
volcanism
biological activity
have ben dropping for the past 50 mil years
57
The warmer the planet, the more ----------- ------ is emitted
infrared light
58
The planet will warm until the absorption of --------- ----- and emission of ------ ------ are balanced
visible light
infrared light
59
Visible light from the sun shines on planet, some light is --------- and the rest is --------
reflected (as infrared)
absorbed
60
Greenhouse effect (think of how blanket works)
"No u"
visible light gets in the atmosphere which is mostly absorbed and the planet gets hot so infrared light is emitted and the greenhouse gasses absorb and remit this back onto surface (blanket)
61
venus is EXTREMELY hot because
thickass atmosphere, traps lots of heat, greenhouse gas effect
62
PHOTODISSOCIATION:
-- light from sun separates atmospheres' ------
UV
atoms
63
PHOTODISSOCIATION:
the separated atoms from the UV light will-------- asap after --------- each other
reconnect
refinding
64
individual atoms are lighter than molecule so......
can escape easier
64
Solar wind of high energy particles do what to the atoms on mars
knock thema way
65
define crust
low density rock
66
core
high density iron/nickel
67
mantle
medium density rock
68
Earth's magnetic field deflect solar wind particles which...
stops the atmosphere from breaking
69
Asteroids orbit........... they are not large enough to be.....
the sun
spherical
70
half an elliptical is called (YELLOW LINE DIVIDING ELLIPSE)
SEMI-MAJOR AXIS
71
Time of an orbit (period) depends on
semi major axis
72
Jupiter effects the ------ of the asteroids
orbits
73
Orbits in ------ ------------ with Jupiter get ---------
exact resonance
displaced
74
The displaced asteroids form ------ --- along the ring meaning that there are --- asteroids
dark bands
no
75
Largest object in asteroid belt
Ceres
76
Ceres inside has
liquid brine, icy crust, rocky center
77
Vesta is ------ asteroid
largest
78
kuiper belt is x times ----- than asteroid belt
what does it include
20-200 times more massive than asteroid belt
includes several dwarf planets
79
where was kuiper belt formed
outside of frost line
80
Oort cloud
huge spherical cloud of comets
81
Comets in oort cloud were formed near -------- but kicked out by ---------- ---------
JUPITER
gravitational interactions
82
how many objects in oort cloud
trillions
83
meteorites are
asteroids that hit earth
84
Outside frost line, --- temperature allow --------- planets to include ------ molecules like H20m Nh4 and Ch4
low
condensing
volatile
85
Where are Terrestrial planets formed inside
INSIDE FROST LINEEE
86
Juno space probe is doing what rn
orbiting jupiter
87
Jupiter inside
Before impact:
Just after impact:
Present day:
Dense core
dilute core
Well developed dilute core
88
Hydrogen can turn form gas to liquid to metal if......... who has this?
theres enough pressure
Jupiter has towards the center
89
Ammonia clouds are what colur
white
90
What varies as you enter jupiter?
temperature and pressure
91
Red bands on jupiter are lower--------- clouds, which are ---------- and brighter
altitude
warmer
92
White bands on jupiter are higher---- clouds which are ------- therefore emit ------ infrared light
altitude
cooler
less
93
Saturns hexagon has a huge what
hurricane
94
Saturns rings are over ------km but less than ---km thick
260,000
0.1
95
Neptune and uranus are called ice giants because
they are big with icy and rocky cores
96
Neptune is
furthest from sun
28 degree tilt
strongest winds
97
Uranus
coldest planet
thick water + ammondia + methane mantle
98
who has thick water + ammondia + methane mantle
uranus
99
very old created surface mostly made of ices, thin brown layer over ice with giant ridge
Iaeptus
100
one of most reflective object in solar system (HIGH ALBEDO)
enceladus (a saturn moon)
101
what does high albedo mean
highly reflective surface
102
Heavily cratered, very porus (40% empty space), made of ice water
HYPERION
103
When farther from jupiter, tidal forces are
less
104
When closer to jupiter, tidal forces are
more
105
The relationship between the tidal forces when close and far away from jupiter causes ------. This is also called ------ -------. This removes --------- out of orbit so it gradually becomes circular
friction
tidal heating
energy
106
Gravitational tugs by Europa and Ganymede (fellow moons) does what to its fellow moon
Makes IO's orbit still elliptical
107
Small moon ------ creates the ----- gap via what resonance ratio
mimas
huygens
2:1
108
bascially moons cause what on rings
deflect particles out of that ring within saturns ring
109
Waves on the disk (saturns ring) also caused by
tiny moon making thin gap
110
Not all wavelengths of light are allowed to travel....
travel through the atmosphere
111
On atmospheric absorption graph, 0 means
no light reaches surface
112
turbulence in earths atmospheres distorts the....
images we see from telescopes
113
For long exposure and large telescopes, turbulence...
blurs image
114
HOBBLE telescope
telescope in earths orbit that is above the atmosphere, 5-10x better resolution
115
How did voyager probes use planets gravity to advantage (think slingshot)
When they lined up, it used each planets gravity to accelerate or slingshot itself to the next
116
Transfer orbit steps
1. start in inner orbit
2. engine burn to speed up
3. Now in the transfer orbit
4. Do a 2nd burn to speed up
5. end in outer orbit
117
when is fuel used during transfer orbit. whats happening when ur not using fuel?
fuel used when you boost in step 2 and 4.
Laying in orbit
118
Inner solar system uses solar pannels to convert -------to -------
sunlight]\
electricity
119
Outer solar system uses RADIOISOTOPE THERMOELECTRIC GENERATOR TO generate electricity using
radioactive plutonium
120
Exoplanet means
a planet orbiting star thats not sun
121
star NAME then "NAME a", "NAME b", "NAME c"
Naming system for exoplanets
122
exoplanets are very faint compared to their
parent star
123
through a standard microscope, exoplanets are
essentially invis
124
Exoplanets are hard to see directly beacause
the parent star bright light shining coveres them
125
Indirect methods
transit method (2969 planets found)
doppler method/radial velocity (863 found)
126
when one celestial object passes in front of another from our POV it is called
a transit
127
seeing Venus in front of sun from earth (OUR POV) is example of
transit
128
Transit method measures the
light curves
129
transits only occur if the planets orbit happens to be
edge on as viewed from earth
130
A dip on the transit graph tells us
a planet blocking the brightness of the parent star (EXOPLANET!!!)
131
the deep dips are --------- and the half way deep dips are --------
planet transits
eclipses
132
THE DEEPER THE TRANSIT,....
THE BIGGER THE EXOPLANET
133
Difference between night and day sides of transits give us
Temperature
134
Getting exoplanets spectrum
(Star + planet spectrum) - (star spectrum) = Exoplanet spectrum
135
What is KEPLER
a transit machine
136
why is kepler useful
the transits it records is much cleaner
137
Find periodic spacing by
seeing the big dip and finding the half of it, then finding smallest dip and finding the double of that
138
For multiple planets periodic spacing has a requirement, whats that
planet 2 has to be bigger and block more light
139
KEPLER HAS SHOWN THAT THERE ARE MANY MORE ----- THAN ----- EXOPLANETS
SMALL
large
140
small exoplanet numbers are all HUGE underestimates because
smaller ones are harder to findddd
141
large exoplanet numbers are also underestimates because
they have long orbital periods so maybe we aren't observing for long enough to know
142
weakness of transit
can only see exoplanets edge on
needs continuous monitor
biased towards close-in
only way to find small exoplanets is from space
143
overal transit method gives us..... of exoplanets
Size
Temp
Periodic spacing
Spectrum
144
Strengths or transit method
does not need big telescope
can detect very small exoplanets
ONLY way to measure size
atmospheric composition
145
IF exoplanets have extra moons or rings, we would see
extra very small dips like super small in the original dip
146
Doppler effect for light:
Spectra
147
Redshifted lines
moving away (longer wavelength0
148
Blueshifted lines
Moving closer to us (shorter wavelength)
149
more severe blue/red shift towards either direction means
speed is faster
150
Doppler only measures line of sight:
For object moving DIRECTLY away, we measure
all its speed
151
Doppler only measures line of sight:
For object moving ACCROSS line of sight, we measure
none of its speed
152
Doppler only measures line of sight:
objects moving diagonally
Only part of its speed
153
The only part of motion we can measure in all cases of Doppler line of sight measures is called
radial velocity
154
KEPLERS 1ST LAW OF ORBIT
Planets orbit sun in elliptical , with sun at focus
155
why is keplers first law wrong
Planets and stars BOTh orbit the center of mass, but stars are so big that they don't move much
156
Why don't stars move much when orbiting centre of mass
they are so massive that usually they are basically/veryclose to the centre of mass
157
A star wobbling towards and away from us is
What our POV sees when a star is "orbiting" the centre of mass
158
exoplanet moves in large orbits but cannot be seen
parent star moves in tiny orbits and is bright enough to see
how can doppler affect be applied
using doppler effect to the spectrum of the star to measure the radial velocity (WOBBLE) of the star as it orbits
159
Doppler method observes the spectrum of the ----- NOT the ------
star NOTT
planet
160
Keplers third law
p^2/m^2 is same for all planets
161
Most common type of exoplanet found in BOTH search types jupiters
HOT JUPITERS
162
51 peg b
first exoplanet found, 0.53 AU
half the mass of jupiter, but closer to sun
163
hot jupiters current thinking
they FORM in outer system, move inward
164
term for "formed in outer system, move inward"
planetary migration
165
Hot jupiters are common because
they are easier to find, they make deeper light scale deeps.
166
Hot jupiters are heavy and close-in meaning for doppler,
they produce large wobble in parent star
167
Hot jupiters are heavy and close-in meaning for TRANSIT,
they make deep transit in parent star's light curves.
168
term for "wobble or transit repeats quick"
Close-in
169
Hot jupiters dominance is an
observational bias
170
Is it usually possible to detect inclination of the orbit
nope
171
we only have a lower limit on true doppler velocity,
we only know the minimum possible mass of exoplanet
WHEN......
when we find an exoplanet via doppler method
172
If exoplanet als transits, we know it must be orbiting nearly ----------, so we know its actual ------ and ------
EDGE ON
mass and size
173
doppler weakness
neeed big telescope
only measure minumum mass unless we know inclination
only study one star at a time
173
doppler method strenght
no continuous monitor
works for any orientation (besides face-on)
very good for massive planets in close-in orbits
174
Combining transit method (size and inclination) and doppler method (mass) gives us
density
175
dotted lines on graph plots mean
various possible densities
176
solar system planets on graph plots are what colur
green
177
selected transiting exoplanets are what colour
red
178
kepler 11f
same mass as earth but twice the size
179
kepler 10b size and density
double size of earth
similar density to lead
180
Angular size of an objet depends on
how big and far away an object is
181
LIFE IS EVERYWHERE IN UNIVERSE, GETS TRANSPORTED FROM NEW ASTWROUDS
PANSPERMIA
182
LUFE AROSE ON EAERTH FROM NATURAL PROCESSES, INORGANIC MATERIAL CONVERSIONS
ABIOGENESIS
183
nutrients (easy)
Energy - sunlight, heat etc (easy)
liquid water (HARD)
requirements for life
184
Habitable zone
orbits where a terrestrial planet could have liquid water on surface
185
What are ESI scores
earth similarity index 0-1, based on exoplanets similarity to earth
186
FERMI PARADOX
optimisitc view of the drake equation
187
drake equation
of intelligent civilizations =
Nhp x f life x fciv x fnow
