I. General Characteristics

Mass 1.898 X 1027 kg = 317.7 Earth
Radius at 1 bar 71492 km = 11.21 Earth
g = GM/r2 23.12 m/s2
Mean Density 1.33 g/cm3
inclination to ecliptic 1.3o
inclination of equator to orbit 3.12o
Rotation Period 9.925 hours
Mean orbital distance 5.2 AU
Orbital period 11.86 years
Mean orbital velocity 13.07 km/s
eccentricity 0.048
temperature at 1 bar 165 K
effective temperature 124 K


Mass 5.69 X 1026 kg = 95.2 Earth
Radius at 1 bar 60268 km = 9.45 Earth
g = GM/r2 8.96 m/s2
Mean Density 0.69 g/cm3
inclination to ecliptic 2.49o
inclination of equator to orbit 26.73o
Rotation Period 10.656 hours
Mean orbital distance 9.555 AU
Orbital period 29.42 years
Mean orbital velocity 9.67 km/s
eccentricity 0.056
temperature at 1 bar 134 K
effective temperature 95 K
At first glance, the 4 Gas Giants appear very similar in many ways. In other ways, however, they are quite different. An analogy is to a family of 4 siblings -- each have similarities, but often the differences are striking, and have to do with genetic makeup as well as environmental factors such as birth order. I hope this material can help to convince you that the differences in the Gas Planets are rooted in how and where they formed. These planets comprise 99.5% of the planetary mass in our solar system -- understanding them is intimately linked to the understanding of how they formed.

II. Composition in Context

Chemistry/Composition still an active research area
in equilibrium, most C in methane, N in ammonia, and O in water
ethane (C2H6), acetylene (C2H2), CO imply dis-eqilibrium (could be photodissociation products)
vertical mixing & inhibited chemical reactions

III. Interior (Ch. 14)

IV. Clouds and Circulation

Magnetic Field

Jupiter's Rings


Internal Energy


Magnetic Field