Transcript Jovian Planets and Satellites

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