life sustaining what’s needed of stars? stablility
TRANSCRIPT
Life Sustaining
What’s needed of stars?
Stablility
Worthless Stars
Worthless Stars
Unstable
Life Sustaining
What’s needed for stars?
Stablility
Long Life
Worthless Stars
UnstableShort Life
Too Hot
Too Cold
Life Zone
Life ZoneLife Zone Too CloseTidal LockOne Side HotOther Side ColdOne Side Baked DryOther Side GlaciersThin Atmosphere
Life Sustaining
What’s needed for stars?
Stablility
Long Life
Life Zone Far From Star
Worthless Stars
UnstableShort Life
Life Zone Too
Close
Life Zone Too Close
H2
He
CH4 NH3 H2O N2 O2 CO2
2 4 16 17 18 28 32 44
Average Speeds at Room Temperature
0
5
10
15
20
25
30
35
40
45
0 100 200 300 400 500 600 700 800 900
Temperature (Kelvin)
Velo
city
(km
/sec
)
Jupiter
EarthVenus
NeptuneUranus
Saturn
H2
He
CH4 NH3 H2O
Holding an Atmosphere
0
3
6
9
12
15
0 100 200 300 400 500 600 700 800 900
Temperature (Kelvin)
Vel
ocity
(km
/sec
)
EarthVenus
Mars
TitanMercury
CH4 NH3 H2O
N2
O2
CO2
H2
He
Holding an Atmosphere
0
1
2
3
4
5
0 100 200 300 400 500 600 700 800 900
Temperature (Kelvin)
Vel
ocity
(km
/sec
)
Titan
Mercury
Moon
Ceres
PlutoTriton
CH4 NH3 H2ON2
O2
CO2
Holding an Atmosphere
Making Contact
seeds of life
evolution
civilization
technology
Two Types of PlanetsTwo Types of PlanetsTerrestrial
Meteor Craters / Erosion
Smaller
Jovian
Only Clouds Visible
Much Bigger
Wed 9:20
Jovians are BiggerJovians are Bigger
Two Types of PlanetsTwo Types of PlanetsTerrestrial
Meteor Craters / Erosion
Smaller
Rocky
High Density
Jovian
Only Clouds Visible
Much Bigger
Mostly Gas
Low Density
Terrestrials are more DenseTerrestrials are more Dense
Jovians Terrestrials
Jupiter 1.33 g/cm3
Mercury 5.43 g/cm3
Saturn 0.70 g/cm3
Venus 5.24 g/cm3
Uranus 1.30 g/cm3
Earth 5.515 g/cm3
Neptune 1.64 g/cm3
Mars 3.94 g/cm3
Two Types of PlanetsTwo Types of PlanetsTerrestrial
Meteor Craters / Erosion
Smaller
Rocky
High Density
Low Mass
Jovian
Only Clouds Visible
Much Bigger
Mostly Gas
Low Density
High Mass
Jovians are more MassiveJovians are more Massive
Jovians Terrestrials
Jupiter 318 M
Mercury 0.0553 M
Saturn 95 M
Venus 0.8150 M
Uranus 14.5 M
Earth 1 M
Neptune 17 M
Mars 0.1074 M
Two Types of PlanetsTwo Types of PlanetsTerrestrial
Meteor Craters / Erosion
Smaller
Rocky
High Density
Low Mass
Few Moons
Jovian
Only Clouds Visible
Much Bigger
Mostly Gas
Low Density
High Mass
Many Moons
Jovians have more MoonsJovians have more Moons
Jovians Terrestrials Jupiter 16 Mercury 0
Saturn 23? Venus 0
Uranus 15 Earth 1
Neptune 8 Mars 2
Two Types of PlanetsTwo Types of PlanetsTerrestrial
Meteor Craters / Erosion
Smaller
Rocky
High Density
Low Mass
Few Moons
No Rings
Jovian
Only Clouds Visible
Much Bigger
Mostly Gas
Low Density
High Mass
Many Moons
Rings
Jovians are farther from the sun.Jovians are farther from the sun.
Jovians Terrestrials Jupiter 5AU Mercury 0.4AU
Saturn 10AU Venus 0.7AU
Uranus 19AU Earth 1AU
Neptune 30AU Mars 1.5AU
What About Pluto?What About Pluto?Plutonoids Pluto
diameter 0.18 Dmass 0.002 M
density 1.97 g/cm3 moons 1
collapse to disk
gravity
centrifugal effect
AccretionAccretionProcess by Which Many Little Things
Become Fewer, Bigger ThingsCondensation
Cold Weld
Tues 12:15
AccretionAccretion
GravityPlanetesimals
Jovian Atmospheres
sweeps up dust while orbitingcollisions slow
orbitspirals in
protosun becomes sunsolar wind clears dust
planetesimals exposed to heat and solar wind
formation limited
no more dust
dust free zone expands
atmosphere reaches escape
velocitysolar wind
blows away atmosphere
planetesimal exposed to heat and solar wind
jovian planet becomes terrestrial
orbit stabilizes
H2
He
CH4 NH3 H2O N2 O2 CO2
2 4 16 17 18 28 32 44
Average Speeds at Room Temperature
0
5
10
15
20
25
30
35
40
45
0 100 200 300 400 500 600 700 800 900
Temperature (Kelvin)
Velo
city
(km
/sec
)
Jupiter
EarthVenus
NeptuneUranus
Saturn
H2
He
CH4 NH3 H2O
Holding an Atmosphere
bombardment
melts surface
heats impact site
Making TerrestrialsMaking Terrestrials
Solar WindLoss of Atmosphere
BombardmentFission
Differentiation
DifferentiationDifferentiation
DifferentiationDifferentiation
DifferentiationDifferentiation
New AtmosphereNew AtmosphereBombardment Slows
Surface HardensMolten Interior
Fission GasOutgassing
CO2 N2 SO2
O2
fissionoutgassing
fissionoutgassing
0
3
6
9
12
15
0 100 200 300 400 500 600 700 800 900
Temperature (Kelvin)
Vel
ocity
(km
/sec
)
EarthVenus
Mars
TitanMercury
CH4 NH3 H2O
N2
O2
CO2
H2
He
Holding an Atmosphere
0
1
2
3
4
5
0 100 200 300 400 500 600 700 800 900
Temperature (Kelvin)
Vel
ocity
(km
/sec
)
Titan
Mercury
Moon
Ceres
PlutoTriton
CH4 NH3 H2ON2
O2
CO2
Holding an Atmosphere
Moon OriginMoon Origin
Fission
Coformation
Capture
Impact
FissionFission
Moon and Earth split
Why?
CoformationCoformation
Moon and Earth formed simultaneously as Binary
Planet
Why is the density different?5.5g/cm3 3.3g/cm3
CaptureCaptureEarth and moon formed far apart
passed close
Earth captured moon
unlikely events required
inclination likely to be high
ImpactImpact
ImpactImpact
ImpactImpact
ImpactImpact
Sunlight bombards
planet.
With the right temperature,
clouds form from water vapor.
Clouds reflect sunlight, lowering
temperature.
The lower temperature causes
more clouds to form.
UV
CO2 N2
carbon based lifeplant life
photosynthesislimestone
risessaturatedoxidizes
O2
O2
23% 76%
2 O3
3
UV ozone
Wave action dissolves CO2 in ocean.