Origin of the Structure of the Kuiper Belt During a Dynamical Instability in the Orbits of Uranus and Neptune (

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Origin of the Structure of the Kuiper Belt During
a Dynamical Instability in the Orbits of Uranus
and Neptune (the Nice Model)
Levison, H., Morbidelli, A., VanLaerhoven, C.,
Gomes, R., Tsiganis, K. Icarus, Accepted

• Nathan Kaib
• 5/16/08

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Outline

• Description of Kuiper Belt
• Giant Planet Migration and the Nice Model
• Simulation Results
• Conclusions

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Outline

• Description of Kuiper Belt
• Giant Planet Migration and the Nice Model
• Simulation Results
• Conclusions

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Properties of the Kuiper Belt

• Missing Mass KB only contains 0.01 0.1 Earth
  masses
• Need 2-3 orders of magnitude more mass to
  accrete 100-1000 km bodies

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Properties of the Kuiper Belt

• 10 50 of objects found in resonances with
  Neptune
• Inclinations extend up to 40o

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Properties of the Kuiper Belt

• Contains large population of excited orbits that
  do not pass near planets now
• - Scattered Disk

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Properties of the Kuiper Belt

• Contains double peaked inclination distribution
• Hot population
• Cold population

Hot
Cold
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Properties of the Kuiper Belt

• Hot and Cold populations have different
  properties

Hot
Bluer, Larger
Redder, Smaller
Cold
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Properties of the Kuiper Belt

• Cold, low e population has sharp cutoff at 12
  resonance with Neptune

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Outline

• Description of Kuiper Belt
• Giant Planet Migration and the Nice Model
• Simulation Results
• Conclusions

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Planetesimal Scattering
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Outer Planet Migration
N

• Nep, Ura, and Sat much more likely to scatter
  bodies in than eject them
• Jupiters energy kicks are powerful enough to
  eject most bodies

J
U
S
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Outer Planet Migration
Neptune, Uranus, and Saturn migrate outwards and
Jupiter moves in to conserve angular momentum
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Current Planet Configuration
12 MMR
Saturn currently is 1.3 AU beyond the 12 MMR
with Jupiter
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The Nice Model
12 MMR
35 AU
If there were 10s of Earth masses of material
beyond Neptune originally, then Saturn must have
crossed the 12 MMR with Jupiter
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• Saturn crossing 12 MMR causes orbits of U and N
  to become chaotic
• Dynamical friction due to scattering damps
  re-circurlarizes orbits

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Nice Model Can Explain

• Cataclysmic Late Heavy Bombardment 3.8 Gyrs ago
• High inclinations of Jovian Trojans
• Existence of cometary bodies in main asteroid
  belt
• Significant non-zero inclinations and
  eccentricities of giant planets
• Irregular satellite populations of giant planets

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Nice Model Can Explain

• Cataclysmic Late Heavy Bombardment 3.8 Gyrs ago
• High inclinations of Jovian Trojans
• Existence of cometary bodies in main asteroid
  belt
• Significant non-zero inclinations and
  eccentricities of giant planets
• Irregular satellite populations of giant planets

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Nice Model Can Explain

• Cataclysmic Late Heavy Bombardment 3.8 Gyrs ago
• High inclinations of Jovian Trojans
• Existence of cometary bodies in main asteroid
  belt
• Significant non-zero inclinations and
  eccentricities of giant planets
• Irregular satellite populations of giant planets

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Nice Model Can Explain

• Cataclysmic Late Heavy Bombardment 3.8 Gyrs ago
• High inclinations of Jovian Trojans
• Existence of cometary bodies in main asteroid
  belt
• Significant non-zero inclinations and
  eccentricities of giant planets
• Irregular satellite populations of giant planets

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Nice Model Can Explain

• Cataclysmic Late Heavy Bombardment 3.8 Gyrs ago
• High inclinations of Jovian Trojans
• Existence of cometary bodies in main asteroid
  belt
• Significant non-zero inclinations and
  eccentricities of giant planets
• Irregular satellite populations of giant planets

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Outline

• Description of Kuiper Belt
• Giant Planet Migration and the Nice Model
• Simulation Results
• Conclusions

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Simulations

• Start planets at last scattering between Uranus
  and Neptune
• Surround Neptunes orbit with torus of 60,000
  test particles extending to 34 AU
• Vary Neptunes starting place and e-damping in
  sims

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Simulations
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Observed
Simulated
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Results Summary
Kuiper Belt Mass Simulations predict 0.05 to 0.14 Earth masses
Resonant Populations Inclinations and eccentricities reproduced well
Scattered Disk Distribution of a and q reproduced
Bimodal Inclinations Reproduced
Physical Differences in Hot and Cold Pops Cold and Hot bodies originate in different areas
12 Resonance Cold Boundary Cold pops. all stop near 12 MMR
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Results Summary
Kuiper Belt Mass Simulations predict 0.05 to 0.14 Earth masses
Resonant Populations Inclinations and eccentricities reproduced well
Scattered Disk Distribution of a and q reproduced
Bimodal Inclinations Reproduced
Physical Differences in Hot and Cold Pops Cold and Hot bodies originate in different areas
12 Resonance Cold Boundary Cold pops. all stop near 12 MMR
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Results Summary
Kuiper Belt Mass Simulations predict 0.05 to 0.14 Earth masses
Resonant Populations Inclinations and eccentricities reproduced well
Scattered Disk Distribution of a and q reproduced
Bimodal Inclinations Reproduced
Physical Differences in Hot and Cold Pops Cold and Hot bodies originate in different areas
12 Resonance Cold Boundary Cold pops. all stop near 12 MMR
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Observed
Simulated
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Results Summary
Kuiper Belt Mass Simulations predict 0.05 to 0.14 Earth masses
Resonant Populations Inclinations and eccentricities reproduced well, Numbers?
Scattered Disk Distribution of a and q reproduced
Bimodal Inclinations Reproduced
Physical Differences in Hot and Cold Pops Cold and Hot bodies originate in different areas
12 Resonance Cold Boundary Cold pops. all stop near 12 MMR
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Results Summary
Kuiper Belt Mass Simulations predict 0.05 to 0.14 Earth masses
Resonant Populations Inclinations and eccentricities reproduced well, Numbers?
Scattered Disk Distribution of a and q reproduced
Bimodal Inclinations Reproduced
Physical Differences in Hot and Cold Pops Cold and Hot bodies originate in different areas
12 Resonance Cold Boundary Cold pops. all stop near 12 MMR
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Observed
Simulated
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Results Summary
Kuiper Belt Mass Simulations predict 0.05 to 0.14 Earth masses
Resonant Populations Inclinations and eccentricities reproduced well, Numbers?
Scattered Disk Distribution of a and q reproduced
Bimodal Inclinations Reproduced
Physical Differences in Hot and Cold Pops Cold and Hot bodies originate in different areas
12 Resonance Cold Boundary Cold pops. all stop near 12 MMR
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Results Summary
Kuiper Belt Mass Simulations predict 0.05 to 0.14 Earth masses
Resonant Populations Inclinations and eccentricities reproduced well, Numbers?
Scattered Disk Distribution of a and q reproduced
Bimodal Inclinations Reproduced
Physical Differences in Hot and Cold Pops Cold and Hot bodies originate in different areas
12 Resonance Cold Boundary Cold pops. all stop near 12 MMR
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Results Summary
Kuiper Belt Mass Simulations predict 0.05 to 0.14 Earth masses
Resonant Populations Inclinations and eccentricities reproduced well, Numbers?
Scattered Disk Distribution of a and q reproduced
Bimodal Inclinations Reproduced
Physical Differences in Hot and Cold Pops Cold and Hot bodies originate in different areas
12 Resonance Cold Boundary Cold pops. all stop near 12 MMR
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Results Summary
Kuiper Belt Mass Simulations predict 0.05 to 0.14 Earth masses
Resonant Populations Inclinations and eccentricities reproduced well, Numbers?
Scattered Disk Distribution of a and q reproduced
Bimodal Inclinations Reproduced
Physical Differences in Hot and Cold Pops Cold and Hot bodies originate in different areas
12 Resonance Cold Boundary Cold pops. all stop near 12 MMR
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Results Summary
Kuiper Belt Mass Simulations predict 0.05 to 0.14 Earth masses
Resonant Populations Inclinations and eccentricities reproduced well, Numbers?
Scattered Disk Distribution of a and q reproduced
Bimodal Inclinations Reproduced
Physical Differences in Hot and Cold Pops Cold and Hot bodies originate in different areas
12 Resonance Cold Boundary Cold pops. all stop near 12 MMR
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Results Summary
Kuiper Belt Mass Simulations predict 0.05 to 0.14 Earth masses
Resonant Populations Inclinations and eccentricities reproduced well, Numbers?
Scattered Disk Distribution of a and q reproduced
Bimodal Inclinations Reproduced
Physical Differences in Hot and Cold Pops Cold and Hot bodies originate in different areas
12 Resonance Cold Boundary Cold pops. all stop near 12 MMR
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Observed
Simulated
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Results Summary
Kuiper Belt Mass Simulations predict 0.05 to 0.14 Earth masses
Resonant Populations Inclinations and eccentricities reproduced well, Numbers?
Scattered Disk Distribution of a and q reproduced
Bimodal Inclinations Reproduced
Physical Differences in Hot and Cold Pops Cold and Hot bodies originate in different areas
12 Resonance Cold Boundary Cold pops. all stop near 12 MMR
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Conclusions

• Nice Model reproduces more properties of Kuiper
  Belt than any other previous scenario
• Eccentricities of cold belt too high by a factor
  of 2
• May be due to unaccounted for physics such as
  collisional damping