Jovian Planets and Satellites Realm of the Cold and Dark

Jovian vs. Terrestrial Density: Jovian, 1 to 2; Terrestrial, 3 to 5 Composition: Jovian, hydrogen + helium; Terrestrial, rocks + metals State: Jovian, liquids + gases; Terrestrial, solids + plastics Jovian larger than Terrestrial

Jovian vs. Terrestrial Jovian more massive than Terrestrial More internal energy at birth Ratio mass/surface area less, lose energy at slower rate Longer evolutionary lives, but no markers (solid surfaces)

Atmospheres Upper layers visible; no distinct solid surfaces lower down Thick: gases of hydrogen, helium, methane, ammonia Weather driven by heat from interior (convection)

Interiors Mantles: Density layers with gradual transitions; gases and liquids (lots of hydrogen) plus ices (methane, ammonia) Cores: Rocky with some metals (earthlike); hot (few 10,000 K); temperature falls from center outward

Energy Outflow Jupiter, Saturn, Neptune emit about twice as much energy as received from sun Emit about 100 times that of the earth per square meter Implies large store of internal heat (massive!)

Satellites (Lots!) Most are mixtures of ices + rocks (density about 2) Scant evidence of volcanism and tectonics on majority Heavily cratered terrain about 4 Gy old, unevolved

Ring Systems Small (baseball) to large (houses) sizes, independent orbits (Kepler’s laws) Icy (bright) and carbon (dark) surfaces In equatorial plane of planet Result of tidal forces