Presentation on theme: "THE STRUCTURE AND EVOLUTION OF MEDIUM SIZED ICY BODIES Uri Malamud Acknowledgment: Dina Prialnik Department of Geophysics, Atmospheric, and Planetary Sciences."— Presentation transcript:
THE STRUCTURE AND EVOLUTION OF MEDIUM SIZED ICY BODIES Uri Malamud Acknowledgment: Dina Prialnik Department of Geophysics, Atmospheric, and Planetary Sciences
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
Can life exist elsewhere? 1.Sentient life evolving on planets 2.Habitable Zone Habitable Zone
Why Modeling? Europa Enceladus Titan
How does a Model work? Properties EnergySources Processes Composition Structure Physical Traits Internal External Heat Transport Thermodynamics Multiphase Flow MODEL
Modeling of Structure&Evolution Exception: active comets ! IDEAL CASE REAL CASE Prototype object Individual object (affected by internal factors) (affected by environment) Equilibrium Few free parameters Known input physics/chemistry Testable by observations (hydrostatic, thermal…) (processes, properties) No equilibrium (dependence on initial conditions) Multi – parameter family Uncertain input physics/chemistry Untestable (ambiguous) (Icy bodies) Stars !
Structure 1.Differentiated structure is postulated. 2.Modeling Heating sources. 3.Thermal Evolution. Water Migration Models
Porosity is real
Heat Sources in Larger Icy objects CrystallizationInsolation Long & short lived Radionuclides Tidal Heating Serpentinization
Melting Point Water melting (pressure and solubles). Rock melting (pressure and water saturation).
Significance of Water Migration
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
Pore & Grain Distribution Pore Size Distribution. Dust Transport.