Jovian Planets

1
Jovian Planets

• Basic Properties
• Differential Rotation
• possible because they are fluid
• magnetospheric rotation rate
• core rotation
• axial tilt
• Jupiter's Atmosphere
• Great Red Spot
• twice Earth's diameter
• composition color
• H2, He, trace gases
• chemical processes produce colors

2

• Jupiter's Atmosphere
• Zones Belts
• due to convective motions
• different heights gt different temps gt different
  colors
• zonal flow
• equatorial speed jet stream
• disappears near poles
• atmospheric structure
• color depth
• stratosphere
• haze layer
• troposphere
• weather convection
• color layers
• weather patterns
• hurricanes
• supported by large-scale atmospheric motion

3

• Weather patterns
• white ovals
• brown ovals - 20o North
• lack of continents gt long life

4
Jovian Atmospheres

• Saturn
• banded, with storms, not as colorful
• hydrogen helium dominate
• helium depletion
• colder temps
• lower gravity gt thicker layers
• equatorial zonal flow _at_ 1500 km/h
• Uranus Neptune
• same general composition
• methane provides colors
• no ammonia (due to lower temps)

5

• Uranus
• clouds at lower levels
• hard to see structure/bands
• flow patterns in rotation direction
• speeds 200-500 km/h
• Neptune
• slightly warmer upper atmosphere
• thinner haze layer
• cloud layers less dense
• equatorial winds
• retrograde
• 2000 km/h
• Great Dark Spot

6
Jovian Interiors

• Cloud cover few hundred km
• Internal Structure
• temp pressure increase with depth
• 20,000 km
• pressure is 3 mill times greater than on Earth
• hydrogen in metallic state
• dense core
• 10 times Earth's mass
• molten rock terrestrial planets
• pressure 50 million times Earth's
• about 20,000 km in diameter
• rotation creates equatorial bulge ( 7 )

7

• Saturn
• metallic hydrogen layer is thinner
• central dense core 15 Earth masses
• lower mass gt less extreme core temp, density,
  pressure
• Uranus Neptune
• no metallic layer
• slushy interiors
• thick layers of highly compressed water clouds
• possibly ammonia dissolved in water
• cores 10-15 Earth masses
• Magnetospheres
• Jupiter
• rapid rotation conductive fluid
• strongest planetary field
• extensive magnetosphere

8

• Magnetospheres
• Saturn
• smaller mass of metallic hydrogen zone
• 1/20 Jupiter's field
• Uranus Neptune
• strong fields
• Internal Heating
• Jupiter
• emits about twice as much energy as it receives
• heat left over from formation
• Saturn
• radiates 3 times what it absorbs
• not hot enough to dissolve liquid helium
• helium rain 2 billion years ago
• compressional gravitational heating
• Uranus
• no internal heat source

9

• Internal Heating
• Neptune
• emits 2.7 times what it receives
• methane insulation??

10
Pluto

• 40 A.U. From Sun
• bright polar caps/possible craters
• Charon
• largest satellite to planet mass ratio
• tidally locked
• 6.4 days
• captured similar to Earth's Moon
• retrograde rotation
• comparable in mass size to Jovian moons
• Kuiper Belt object?