Bit of Administration ….Bit of Administration ….• ReadingReading

– BSNV Chap. 13BSNV Chap. 13

• PortfoliosPortfolios– Due Due Thursday, April 29Thursday, April 29, because of possible TAA strike, because of possible TAA strike

• Put in box outside 6522 SterlingPut in box outside 6522 Sterling

– All 5 must be All 5 must be securelysecurely bound together, including ones already graded bound together, including ones already graded– Late portfolios will lose creditLate portfolios will lose credit

• Lab 3Lab 3– Due Due Thursday, April 29Thursday, April 29, because of possible TAA strike , because of possible TAA strike

• Put in box outside 6522 SterlingPut in box outside 6522 Sterling

– Problem 5, HW 1 is a good starting point for the lab questionsProblem 5, HW 1 is a good starting point for the lab questions– Note typo in Question 3 - “Jupiter” => “Saturn”Note typo in Question 3 - “Jupiter” => “Saturn”

Jovian RingsJovian Rings

SaturnSaturn

NeptuneNeptune

JupiterJupiter

UranusUranus

Jovian RingsJovian Rings• SaturnSaturn

Cassini’s DivisionCassini’s Division

AA BBCC

Jovian RingsJovian Rings• SaturnSaturn

70, 000 km across …. 20 m thick!70, 000 km across …. 20 m thick!

Jovian RingsJovian Rings• SaturnSaturn

S

AB

RedshiftRedshift

BlueshiftBlueshift

Velocity AVelocity A >> Velocity BVelocity B

Keplerian!Keplerian!

EarthEarth

Jovian RingsJovian Rings• SaturnSaturn

Snowflakes (few microns) to Boulders (10 m)Snowflakes (few microns) to Boulders (10 m)

Jovian RingsJovian Rings• Dynamics - Roche LimitDynamics - Roche Limit

• Radius Inside Which Large Bodies Fragment Due to Tidal ForcesRadius Inside Which Large Bodies Fragment Due to Tidal Forces (i.e., differences in gravitational forces)(i.e., differences in gravitational forces)

Sat1 2

1000 km1 km

Gravitational Force on Moon 2

Gravitational Force on Moon 1€

Fg =GM2MS

10002

€

Fg =GM1MS

10012

1.002 x Greater1.002 x Greater

Jovian RingsJovian Rings

Gravitational Force on Moon 2

Gravitational Force on Moon 1€

Fg =GM2MS

12

€

Fg =GM1MS

22

4 x Greater!4 x Greater!

• Dynamics - Roche LimitDynamics - Roche Limit

• Radius Inside Which Large Bodies Fragment Due to Tidal ForcesRadius Inside Which Large Bodies Fragment Due to Tidal Forces (i.e., differences in gravitational forces)(i.e., differences in gravitational forces)

1 2

1 km

1 km

Sat

Jovian RingsJovian Rings

• Dynamics - Roche LimitDynamics - Roche Limit

• Radius Inside Which Large Bodies Fragment Due to Tidal ForcesRadius Inside Which Large Bodies Fragment Due to Tidal Forces (i.e., differences in gravitational forces)(i.e., differences in gravitational forces)

• Rings formed by …Rings formed by …

• Moon entering within Roche limit?Moon entering within Roche limit?• Material originally inside Roche limit that neverMaterial originally inside Roche limit that never formed a moon?formed a moon?• Slow destruction of small moons within Roche limit Slow destruction of small moons within Roche limit by micrometeorites?by micrometeorites?

Jovian RingsJovian Rings

• Dynamics - Cassini Division - Tidal ResonanceDynamics - Cassini Division - Tidal Resonance Suppose ….Suppose ….

Jovian RingsJovian Rings

• Dynamics - Cassini Division - Tidal ResonanceDynamics - Cassini Division - Tidal Resonance Suppose ….Suppose ….

S

S

S

MimasMimas

Jovian RingsJovian Rings

• Dynamics - Cassini Division - Tidal ResonanceDynamics - Cassini Division - Tidal Resonance

• Orbital Period of Mimas is 2x Orbital PeriodOrbital Period of Mimas is 2x Orbital Period of particles in Cassini’s Divisionof particles in Cassini’s Division

“ “2 to 1 Resonance”2 to 1 Resonance”

• Repeated gravitational pulls clear gap at that orbit.Repeated gravitational pulls clear gap at that orbit.

Jovian RingsJovian Rings

• Dynamics - Shepherd SatellitesDynamics - Shepherd Satellites

100 km100 km

Jovian RingsJovian Rings

• Dynamics - Shepherd SatellitesDynamics - Shepherd Satellites

SaturnSaturn

Jovian RingsJovian Rings

• Dynamics - Shepherd SatellitesDynamics - Shepherd Satellites

Jovian RingsJovian Rings

• Uranus and NeptuneUranus and Neptune

Jovian RingsJovian Rings

• Uranus and Neptune - WeatherUranus and Neptune - Weather

Jovian RingsJovian Rings

• Uranus and Neptune - WeatherUranus and Neptune - Weather

Jovian RingsJovian Rings

• Uranus and Neptune - Interior StructureUranus and Neptune - Interior Structure

Jovian RingsJovian Rings

• Uranus and Neptune - Rotation and Magnetic FieldsUranus and Neptune - Rotation and Magnetic Fields

Jovian RingsJovian Rings

• Uranus and Neptune - MoonsUranus and Neptune - Moons

Retrograde, inclined orbit Retrograde, inclined orbit - captured?- captured?

38 38 ooKK

Jovian PlanetsJovian Planets• SummarySummary

• Weather (“Atmospheric Dynamics”)Weather (“Atmospheric Dynamics”)• Driven by energy flowsDriven by energy flows

• Thermal from interiorThermal from interiorResidual heat from formationResidual heat from formationOngoing contractionOngoing contraction

• Gravity (highs to lows)Gravity (highs to lows)• Solar radiationSolar radiation

• Rapid rotation + Coriolis leads to twisting motionsRapid rotation + Coriolis leads to twisting motions

• Magnetic fieldsMagnetic fields• Result fromResult from

• Liquid metallic interiorsLiquid metallic interiors• RotationRotation• ConvectionConvection

Jovian PlanetsJovian Planets

• SummarySummary

• Giant MoonsGiant Moons• Ice and rock (from condensation sequence)Ice and rock (from condensation sequence)• Dynamically active (due to tidal forces)Dynamically active (due to tidal forces)• Atmospheres (Io, Titan, Triton)Atmospheres (Io, Titan, Triton)• Liquid oceans (Europa?, Titan?)Liquid oceans (Europa?, Titan?)• Life ?Life ?

Asteroids, Comets, Meteors, and PlutoAsteroids, Comets, Meteors, and Pluto

Asteroids, Comets, Meteors, and PlutoAsteroids, Comets, Meteors, and Pluto

Asteroids, Comets, Meteors, and PlutoAsteroids, Comets, Meteors, and Pluto

• AsteroidsAsteroids

Asteroids, Comets, Meteors, and PlutoAsteroids, Comets, Meteors, and Pluto

• AsteroidsAsteroids

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