Tour of the Outer Planets

Our first stop… Jupiter!

• Largest planet in the solar system• 63 named moons (don’t worry, you only have

to learn four!• 11 times the diameter of Earth• 5 AU from the Sun

What is the surface like? Can we land there?

Great Red Spot

• Giant storm• New spot appeared and then disappeared

days later

Jupiter’s moons (Galilean moons)

Ganymede•Largest moon in the solar system•Larger than Mercury!•Has ice!•Has a magnetosphere•Very thin oxygen atmosphere!

Callisto-2nd largest Galilean moon

• Same size as Mercury

• May have subsurface liquid ocean

• Could hold life in ocean ??

Io- 3rd largest Galilean moon• 400 active SO2

volcanoes due to tidal activity with Jupiter

• Some are taller than Everest

• Rock coated with sulfur dioxide frost

Europa-last, but most important• Smaller than the

Moon• Surface

composed of 100 km thick ice layer

• Liquid ocean underneath

• Thin O2 • Life, microbes?

Next Stop… Saturn!• 10 times the

diameter of Earth

• 10 AU from Earth

• 56 moons (you only need to know ONE!

• Storms on surface

Saturn would float in water

• Titan is the largest moon of Saturn (1.5 times our Moon)

• Made of ice and rock

• Air is nitrogen and methane

• Possible microbial life?

Uranus!!Ice Giant• 4 times

Earth’s diameter

• 19 AU away• More

methane, ammonia than Jupiter

• 27 moons

Sideways rotation• 42 years of

darkness/light• Rings less visible

than Saturn (rock vs. ice)

Ice Giant: Neptune!• Close in size and

composition to Uranus

• Methane gives it the blue color

• Four faint rings• Great Dark Spot• 30 AU from the Sun• Moon, Triton,

revolves in retrograde

• 13 moons

Dwarf Planets• Ceres (in the asteroid belt) about 3 A.U.– Probe will arrive in 2015

• Pluto (Charon)– Two objects in binary

revolution– 40 AU from the Sun– Orbit angled differently

than Earth– Crosses Neptunes orbit

20 out of 248 years

Clyde Tombaugh’s discovery

• Eres• Other TNOs

Comets• Small collections of ice, dust, and rock that

orbit the sun• Some originate in the Kuiper belt, others from

the Oort cloud