Life Sustaining

1
Life Sustaining

• Whats needed of stars?
• Stablility

2
Worthless Stars
3
Worthless Stars
Unstable
4
Life Sustaining

• Whats needed for stars?
• Stablility
• Long Life

5
Worthless Stars
Short Life
Unstable
6
Life Zone
7
Life Zone
Life Zone Too Close Tidal Lock One Side Hot Other
Side Cold One Side Baked Dry Other Side
Glaciers Thin Atmosphere
8
Life Sustaining

• Whats needed for stars?
• Stablility
• Long Life
• Life Zone Far From Star

9
Worthless Stars
Short Life
Unstable
10
Average Speeds at Room Temperature
H2
He
CH4
NH3
H2O
N2
O2
CO2
2 4 16 17 18 28 32 44
11
Holding an Atmosphere
Jupiter
Saturn
Neptune
Uranus
H2
He
Earth
Venus
CH4 NH3 H2O
12
Holding an Atmosphere
H2
He
Earth
Venus
CH4 NH3 H2O
N2 O2 CO2
Mars
Mercury
Titan
13
Holding an Atmosphere
N2 O2 CO2
Mercury
CH4 NH3 H2O
Titan
Moon
Triton
Pluto
Ceres
14
Making Contact

• seeds of life
• evolution
• civilization
• technology

15
(No Transcript)
16
(No Transcript)
17
Two Types of Planets
Wed 920

• Terrestrial
• Meteor Craters / Erosion
• Smaller

• Jovian
• Only Clouds Visible
• Much Bigger

18
Jovians are Bigger
19
Two Types of Planets

• Terrestrial
• Meteor Craters / Erosion
• Smaller
• Rocky
• High Density

• Jovian
• Only Clouds Visible
• Much Bigger
• Mostly Gas
• Low Density

20
Terrestrials are more Dense
21
Two Types of Planets

• Terrestrial
• Meteor Craters / Erosion
• Smaller
• Rocky
• High Density
• Low Mass

• Jovian
• Only Clouds Visible
• Much Bigger
• Mostly Gas
• Low Density
• High Mass

22
Jovians are more Massive
23
Two Types of Planets

• Terrestrial
• 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

24
Jovians have more Moons
25
Two Types of Planets

• Terrestrial
• 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

26
(No Transcript)
27
Jovians are farther from the sun.
28
What About Pluto?
29

30
Accretion
Process by Which Many Little Things Become Fewer,
Bigger Things Condensation Cold Weld
31
Tues 1215
32
Accretion
Gravity Planetesimals Jovian Atmospheres
33
protosun becomes sunsolar wind clears dust
sweeps up dust while orbitingcollisions slow
orbitspirals in

planetesimals exposed to heat and solar
windformation limitedno more dust
34
dust free zone expands
planetesimal exposed to heat and solar wind
atmosphere reaches escape velocity solar wind
blows away atmosphere

jovian planet becomes terrestrial
35
Average Speeds at Room Temperature
H2
He
CH4
NH3
H2O
N2
O2
CO2
2 4 16 17 18 28 32 44
36
Holding an Atmosphere
Jupiter
Saturn
Neptune
Uranus
H2
He
Earth
Venus
CH4 NH3 H2O
37
bombardment
heats impact site
38
Making Terrestrials
Solar Wind Loss of Atmosphere Bombardment Fission
Differentiation
39
Differentiation
40
Differentiation
41
Differentiation
42
New Atmosphere
Bombardment Slows Surface Hardens Molten
Interior Fission è Gas Outgassing CO2 N2 SO2 O2
43
fissionoutgassing
44
Holding an Atmosphere
H2
He
Earth
Venus
CH4 NH3 H2O
N2 O2 CO2
Mars
Mercury
Titan
45
Holding an Atmosphere
N2 O2 CO2
Mercury
CH4 NH3 H2O
Titan
Moon
Triton
Pluto
Ceres
46
Moon Origin

• Fission
• Coformation
• Capture
• Impact

47
Fission

• Moon and Earth split
• Why?

48
Coformation

• Moon and Earth formed simultaneously as Binary
  Planet
• Why is the density different? 5.5g/cm3 3.3g/cm3

49
Capture

• Earth and moon formed far apart
• passed close
• Earth captured moon
• unlikely events required
• inclination likely to be high

50
Impact
51
Impact
52
Impact
53
Impact
54
Clouds reflect sunlight, lowering temperature.
The lower temperature causes more clouds to form.
With the right temperature, clouds form from
water vapor.
55
O2 23 76
CO2 N2
carbon based life plant life photosynthesis limest
one
rises saturated oxidizes O2