Jovian Planets

Composition

Jupiter is composed of 97% H and He Saturn is composed of 90% H and He Uranus and Neptune are CH4 H2O and NH3 Neptune and Uranus are more dense than Jupiter and Saturn Jupiter is more dense than Saturn Beyond frost line where it is possible for H compounds to condense. Form around an icy planetesimal

Jupiter Saturn a = 5.20 AU R = 11.2REarth M = 318MEarth ρ = 1.33 g/cm3

Inside Jupiter Formed around rock and metal core weighing about 10x Earth The rest is H, compressed into strange phases

Inside Other Jovian Planets Similar compositions, but less mass means less of the strange liquid and metallic H (Uranus and Neptune have only gaseous H)

Magnetic Fields Rotating Metallic H creates strong field ~20,000x as strong as Earth’s

Jupiter’s Colors Yellow = NH3 Rust = (NH4)SH Blue/White = H2O

Neptune CH4

Coriolis Effect From the ball’s perspective it makes a straight line From the dot’s perspective, it makes a curve Go to animated version at wikipedia

Jupiter’s fasts rotation creates extreme Coriolis Effect, stretching weather patterns all the way around the planet

The Great Red Spot Been there as long as astronomers have looked at Jupiter 2-3x size of Earth

Similar Weather on Other Planets

Jovian Satellites

150+ known satellites of Jovian planets Largest satellites were likely formed with planets Smaller ones were likely captured Largest satellites resemble terrestrial planets Spherical Solid Surface Geology Hot interiors Atmospheres Magnetic fields

Galilean Satellites

Orbital Resonance When orbital periods of two or more bodies are integer multiples Causes orbits to be more elliptical

Io Most volcanically active body in the solar system Great eruption in 1996 photographed by Galileo Plume extends 60 miles above surface Blue due to frozen sulfur dioxide

Tidal Heating Tidal Friction is caused by elliptical orbit Stronger tides on one side of orbit than other Cause by orbital resonances Tidal Friction heats up the body

Europa Surface covered in water ice Tidal stresses heat water, keep liquid layer under the surface Very few craters, indicates geological activity

Titan Thick atmosphere of 90% N, Hydrocarbons Oceans of methane

Rings

Saturn’s Rings Large gap called “Cassini division” Due to orbital resonance with satellite, Mimas Made up of tons of tiny particles of mostly ice

Gaps Rings caused by particles being bunched up into similar orbital distances Gaps caused by: Small “gap moons” Orbital resonances with larger satellites

Cause of Rings All Jovian planets have rings Not remnants of ancient formation material That material would not last billions of years Must be constantly resupplied Constant collisions of small satellites Get broken down into smaller and smaller pieces