1. THE STRUCTURE AND EVOLUTION OF MEDIUM SIZED ICY BODIES
Uri Malamud
Acknowledgment: Dina Prialnik
Department of Geophysics, Atmospheric, and Planetary Sciences

2. Water in the solar system
Asteroids
Main Belt (disguised comets?)
Trojans
500 km
Comets
Kuiper Belt Objects
Centaurs
Icy Satellites
Long-period (Oort Cloud)
Short-period (Kuiper Belt)
Main Belt (?)
Classical
Plutinos
Scattered

3. Can life exist elsewhere?
Habitable Zone
Sentient life evolving on planets
Habitable Zone

4. Why Modeling?
Europa
Enceladus
Titan

5. How does a Model work? MODEL Processes Properties Energy Sources
Heat Transport
Composition
Thermodynamics
Structure
Multiphase Flow
Physical Traits
MODEL
Energy
Sources
Internal
External

6. Modeling of Structure&Evolution
IDEAL CASE
REAL CASE
(Icy bodies)
Prototype object
Individual object
(affected by internal factors)
(affected by environment)
Equilibrium
No equilibrium
(hydrostatic, thermal…)
(dependence on initial conditions)
Multi – parameter family
Few free parameters
Known input
physics/chemistry
Uncertain input
physics/chemistry
(processes, properties)
Testable by observations
Untestable (ambiguous)
Stars !
Exception: active comets !

7. Water Migration Models
Structure
Differentiated structure is postulated.
Modeling Heating sources.
Thermal Evolution.
Water Migration Models

8. Porosity is real

9. Heat Sources in Larger Icy objects
Insolation
Crystallization
Tidal Heating
Serpentinization
Long & short lived Radionuclides

10. Melting Point Water melting (pressure and solubles).
Rock melting (pressure and water saturation).

11. Physical Description

12. Output

13. Significance of Water Migration

14. Thank You

15. Self Gravity? EOS for compressed porous material.
79 km – highly porous
core depleted of ice
20 km – low porosity
ice-enriched layer
125 km – porous layer
50% crystalline ice
and 50% dust (rock)
7 km – gradual transition
from “a” to “c” ice
19 km – “a” ice and dust
pristine composition
EOS for compressed porous material.

16. Pore & Grain Distribution
Pore Size Distribution.
Dust Transport.