Jovian Planets

1
Jovian Planets

• Reading Ch 9

2
(No Transcript)
3
Jupiter
Gas Giants
Saturn
318 MEarth 11.2 REarth
95.2 MEarth 9.44 REarth
4
Ice Giants
Uranus
Neptune
14.5 ME 4.01 RE
17.1 ME 3.88 RE
5
The Jovian Planets
Earth
Uranus
Neptune
Jupiter
Saturn
6
Brief Property Summaries
7
Jupiter King of the Planets

• Number 1
• Largest Radius
• Largest Mass
• Fastest Rotator
• Highest number of moons
• Great Red Spot
• Atmospheric Activity Belts Zones

8
Saturn Amazing Rings

• Unique Ring Features
• Number in 1000s
• Cassinis Division
• Snowballs in Orbit
• Shepherd Moons
• Lowest Density Planet
• Titan only Moon with an atmosphere

9
Uranus

• -Almost no Internal Heating
• -Featureless Atmosphere
• -Rotation Axis tilted 90º
• Weird Seasons
• -First discovered rings. (Occultation of a
  Star)

10
Neptune

• Highest Internal Heating (Surface is as hot as
  Uranus)
• -360 F
• White Methane Ice Clouds
• Supersonic Jet Streams
• Band Structure
• Great Dark Spots
• 19891994 S.H.
• 1995 N.H

11
Composition

• All parts (atmosphere interior) composed of
• H atomic hydrogen
• H2 molecular hydrogen (gas, liquid)
• Molecules made up of Hydrogen
• Methane CH4
• Ammonia NH3
• Percent Composition (by mass)
• H 80
• He 20
• Everything else Trace amounts

12
Why Hydrogen Helium?

• Primordial Disk (especially its outskirts)
  composed of 80 H , 20 He
• So young Jovian planets accreted these elements
• Young Jovian cores formed from rock/icy
  planetesimals
• Except for some planets EVERYTHING is primarily H
  and He
• Interstellar Clouds/Stars/Galaxies
• Ultimate Reason In first the 15 minutes of the
  Universe, H and He atoms were made in 80/20
  abundance

13
Jovian Composition
80
20
14
Spacecraft Visits Jupiter Saturn

• Fly-bys
• Pioneer 10 11
• (1973/74)
• Voyager 1 2
• (1979)
• Ulysses (1992)
• Cassini (2001)
• Orbiters
• Galileo (arrived Dec 1995, planned crash into
  Jupiter in 2003)
• Dropped an atmospheric probe in Dec 1995

15
Spacecraft Uranus Neptune

• Voyager 2 flew pastUranus Neptune
• Uranus January 1986
• Neptune August 1989
• Both have been extensively studied using the
  Hubble Space Telescope
• Long-term monitoring of weather patterns.
• Infrared imaging studies of their atmospheres,
  rings, and moons.

16
Jupiter Saturn Interiors

• No Solid Surface
• Interior Definition Below the cloud layers
• Pressure becomes high enough to liquefy gases
• Primarily H in many different forms
• Also He (see later)
• Interior Oceans of Hydrogen
• Liquid Molecular Hydrogen in two forms (Normal
  and Metallic)

17
Jupiter
Molecular Hydrogen
Metallic Hydrogen
Rock Ice
10-15 MEarth
18
Saturn
Molecular Hydrogen
Metallic Hydrogen
Rock Ice
10-12 MEarth
19
Uranus Neptune Interiors

• Uranus Neptune are Ice Giants
• Thick, slushy mantles of H2O, NH3 CH4 ices
• Rocky cores about the size of the Earth.
• Shallow atmospheres of H2 He with CH4 haze
• Most of their mass consists of ice
• Lower mass, so lower internal pressure
• Lack metallic hydrogen mantles found in the Gas
  Giants Jupiter Saturn

20
Interiors of Uranus Neptune
Molecular Hydrogen
Rocky Core
Slushy IceMantles
Uranus
Neptune
21
Jovian Planet Interiors
Earth
Uranus
Neptune
Jupiter
Saturn
22
Internal Heat Sources

• Energy imbalance Jovian planets radiate more
  energy than they receive from the Sun
• Extra energy is heat generated in core due to
  SLOW gravitational contraction
• Primordial Jovian planets formed from
  contraction
• Internal Heat sources will power their
  atmospheric activity

23
Infrared Image of Jupiter
24
Jupiter Saturn Atmospheres

• Guess what? Molecules containing Hydrogen
• From top down
• Ammonia Clouds
• Ammonium Hydrosulfide Clouds (NH4HS)
• H2O ice Clouds
• Temperature at the top
• Jup-236 ºF Sat-285 ºF
• Where do the beautiful colors come from?
• Possibly, phosphine (PH3) acting as a dye
• To synthesize phosphine need energy input
  (Internal heat from below!)
• Show rotational flattening

25
Jovian Planetary Structure
26
Atmosphere of Saturn

• The atmosphere is dividedinto dark bands
  bright zones likeJupiter's, but...
• Saturn is farther from the Sun, and colder.
• Cause more muted features
• Less atmospheric Helium (1/4) than Jupiter,
  probably due to rainout in the deep interior.

27
Color-enhanced view of Saturns
Atmosphere showing bands and storm systems. (Cassi
ni image)
28
Uranus Atmosphere

• Uranus is a virtually featureless, hazy blue
  ball.
• Composed of Methane
• Clouds are cold and lie below the haze
• Results in a generally uniform appearance.
• Occasional clouds/storms seen in the infrared.

Clouds
Keck Image (infrared light)
29
Why are Uranus Neptune Blue?
Methane (CH4) Haze
Methane absorbs long wavelengths transparent to
short wavelengths
30
Atmospheric Activity

• Jet Streams
• Largest speeds at Equator
• J 250 mph, S 1000 mph
• Jet stream speeds drop off as move away from
  equator (either N or S)
• Alternate directions
• Dark Belts
• Bright Zones
• Anti-Cyclonic storms
• Jet streams at Belt/Zone boundaries

31
(No Transcript)
32
(No Transcript)
33
Belts Zones of Jupiter

• Belts
• Gaps in high clouds, view lower atmosphere
• Gas is sinking down
• Zones
• Regions of cold, high ice clouds
• Gas is slowly rising

34
Rising/Sinking Cause Convection
35
Atmospheric Activity Storms

• Great Red Spot on Jupiter
• It is a vortex rotational period is 6 days
• Rotates counter clockwise is Southern Hemisphere
• Anti-Cylconic rotation (High Pressure Zone)
• It is HUGE could hold 2 Earths!!
• We dont know when it started
• Or when it will end
• No solid land to provide friction
• Hard to stop something of that size
• Rotation driven by its position between a Zone
  Belt
• Such a permanent formation on Jupiter that
  gases flow around it leaving a turbulent wake

36
Great Red Spot
37
Great Red Spot
38
(No Transcript)
39
Neptunes Atmospheric Activity

• Neptune radiates 2.7x as much energy as it gets
  from the Sun.
• Active atmosphere
• Dark belts
• Bright clouds of methane ice.
• Dark oval cyclonic storms.

40
Neptune Weather
41
Uranus Extreme Seasons
1986
2007
2028
2049

• Uranus axis is tilted 98º
• Lying on its side in its orbit
• Extreme seasonal variations (Every 21 years)
• 1986 North pole overhead in full Sun, South pole
  in darkness
• 2007 Sun on the equator, twilight at poles.
• 2028 South pole in full sunlight, north is dark.