1. Chapter 12
Jupiter and Saturn

2. 12.2 Basic Properties
Jupiter and Saturn are more massive then the Earth in size
Jupiter’s density is only 1.33 times that of water or 25% that of Earths density
This means the planet must be made mainly from lighter elements; hydrogen and helium
Saturn is 85% the size of Jupiter and half the density or 69% that of water
Again it means the planet is mostly hydrogen and helium

3. 12.2 Basic Properties
Jupiter has striped color bands lying parallel to the equator, made from solid and gases materials
It also has lighter and darker spots on it, the great red spot was discovered by Giovanni Cassini in 1665
The colors are more subdued then here on Earth
The equator rotates at 12.5 km/s or more then Earth’s escape velocity, this cause the equator to bulge and the poles to flatten

4. 12.2 Basic Properties
Saturn also has a similar equatorial bulge, caused by a rapid rotation
The color bands are less impressive compared to Jupiter
The color differences are less with fewer spots
More features of the atmosphere was detected in the Voyager images, but still less then Jupiter

5. 12.2 Basic Properties Rotation and winds
Jupiter rotates at 9 hours 50 minutes at the equator and at 9 hours 55 minutes at higher latitudes, this means all we see are clouds and gas
The variation of wind speed by latitude is called zonal winds, the equatorial winds are the equatorial jet
zonal wind speed changes normally have large rotating clouds, the Great Red Spot
The magnetic field rotates in 9 hours 55 minutes

6. 12.2 Basic Properties Rotation and winds Saturn
The equator rotates at 10 hours 14 minutes and higher latitudes at 10 hours 40 minutes
The magnetic field rotates in 10 hours 40 minutes
Saturn has very strong equatorial winds, 500 km/s
These high speed winds are found in all planets upper atmosphere

7. 12.1 Jupiter and Saturn Why are the densities of Jupiter and Saturn so low
Jupiter is 70% of all the planetary material
11 times the diameter of earth and 1/10th that of the sun
Saturn was the most distant planet known to the ancients
Galileo was the first to see the rings

8. Why are the densities of Jupiter and Saturn so low
The main reason that both Jupiter and Saturn have low density seems to be from the planet being formed from Hydrogen and Helium gases, with no apparent solid surface.

9. 12.3 Atmosphere What makes the cloud patterns of Jupiter and Saturn so colorful
The Galileo spacecraft dropped a probe into Jupiter’s atmosphere in December 1995 and then in 2003 crashed itself into the planet
Chemical make up of the planet 99.9% Hydrogen and helium (4 to 1); trace amount of methane, ammonia, water vapor, acetylene, ethane and propane.
Saturn has similar gases with the exception of helium which is at a 7 to 1 ratio

10. 12.3 Atmosphere What makes the cloud patterns of Jupiter and Saturn so colorful
Vertical structure of the atmosphere is determined using the pressure change by altitude
The zero level is completely arbitrary though since there is no solid surface and the atmosphere is temperatures are much cooler at 125K
The troposphere like earth is an area of turbulent gases with raising and falling columns of gas
Saturn has a similar make up as well with even lower temps of 75K

11. 12.3 Atmosphere What makes the cloud patterns of Jupiter and Saturn so colorful
The cloud features of Jupiter, the great red spot (southern hemisphere) is a high pressure zone of raising gases, which means it is bring clouds up from below
The material can take months to raise in the spot giving ultraviolet radiation time to react with the gases
The great red spot seems to have be around for centuries, other spots that are white last for years to decades
The brown spots in the northern hemisphere last for only a few years

12. 12.3 Atmosphere What makes the cloud patterns of Jupiter and Saturn so colorful
Great Red Spot
Has been under observation for the last 350 years, it was fully formed when first observed, it rotates counterclockwise in the southern hemisphere (high Pressure front)
Cloud features sometimes flow along the edge, stop on the westward side and merge or continue on
In the late 1990’s we watched there large white spots merge together, in 2006 the color changed to red and as of 2007 had similar winds as the great Red Spot

13. 12.3 Atmosphere What makes the cloud patterns of Jupiter and Saturn so colorful
Saturn clouds
Seems to have some similar cloud features as Jupiter with raising gases forming spots in the clouds
Most appear to last for a few days and then disappear, some have been seen by both voyager 1 and 2, this means some may last several years

14. 12.3 Atmosphere What makes the cloud patterns of Jupiter and Saturn so colorful

15. 12.3 Atmosphere What makes the cloud patterns of Jupiter and Saturn so colorful
Jupiter's atmosphere shows that it changes over decades, this may be due to the change of the seasons
Temperature, Depth and Convection
The clouds show a complex system of convection or raising and sinking air
The warm clouds bands, brown spots and blue grey regions are low in the troposphere
The Great Red Spot, white ovals and cloud bands are areas of raising cool air
The Coriolis effect is what causes the rotation of the clouds

16. 12.3 Atmosphere What makes the cloud patterns of Jupiter and Saturn so colorful
Atmospheric Coloration – Jupiter
Clouds mainly ammonia, ammonium hydrosulfide and water: Phosphine in the atmosphere and is a coloring agent
the molecules in Jupiter atmosphere scatter blue light

17. 12.4 interiors Why are the interior structure of Jupiter and Saturn so different from those of terrestrial planets
Interiors
Low density of planets means mainly hydrogen and helium
The interior pressure of Jupiter around 50Mb (earth 3.5Mb) and Saturn is greater than 10Mb
The internal temperatures around 20,000 K (35,540 F)

18. 12.4 interiors Why are the interior structure of Jupiter and Saturn so different from those of terrestrial planets
Metallic Hydrogen
As you travel toward the center you slowly transition from a gas to liquid Hydrogen (H2) at around 2 to 3Mb
But there is an abrupt change when all the electrons are pushed out and becomes a shiny metallic material
This means that the core are strong conductors of electricity and help explain the strong magnetic fields

19. 12.4 interiors Why are the interior structure of Jupiter and Saturn so different from those of terrestrial planets
Internal Structure

20. 12.4 interiors Why are the interior structure of Jupiter and Saturn so different from those of terrestrial planets
Internal Energy
Jupiter emits 70% more energy then received from the sun
Saturn emits 50% more energy
Both planets are self luminous
The amounts of energy produced by both planets is only slightly less then some stars

21. internal energy of Jupiter and Saturn (page 280)
12.5 internal energy of Jupiter and Saturn What is the source of the internal energy radiated away by Jupiter and Saturn
internal energy of Jupiter and Saturn (page 280)
Jupiter
Early in the Solar system it could have been a binary stars system, Jupiter second star, 1% brightness of the sun and red in color
Heated up to around 50,000 K, due to surface contraction , a ten fold collapse in the first million years
Contraction is so slow today it can not even be measured
Most internal heat is the left over from the original collapse of the surface

22. internal energy of Jupiter and Saturn (page 280)
12.5 internal energy of Jupiter and Saturn What is the source of the internal energy radiated away by Jupiter and Saturn
internal energy of Jupiter and Saturn (page 280)
Saturn
Saturn is smaller and therefore would cool more quickly then Jupiter
Core temp below 10,000 K allows helium to condense and sink inward, gravitational energy into heat
This shown by the 7 to 1 ratio of hydrogen to helium gas

23. 12.6 internal energy of Jupiter and Saturn What is the source of the internal energy radiated away by Jupiter and Saturn
Magnetospheres
At Jupiter’s cloud tops the magnetic field is 14 times stronger the Earth’s field at the surface
Saturn’s magnetic field is 2/3 that of Earth
Jupiter and Saturn’s field shape is the same as Earths
The size of Jupiter’s field is ten times the size of the sun
Both trap ions in a Van Allen Belt and cause an aurorae at the poles
There moons seem to be the major source of ionized gas

24. 12.7 Rings : pages
Why are the rings of Jupiter and Saturn so thin compared with their diameters?
How can we account for the complex structure of the rings of Saturn?