What Do the Outer Planets Have in Common?

What Are the Characteristics of Each Outer Planet?

LargeGas giants (no

solid surface)

Hydrogen and helium Ices of ammonia and methane Strong gravitational forces (due to their

size) keep these gases from escaping Much of the material in gas planets is

actually liquid because the pressure inside the planet is so high

The outer layers are extremely cold Temperature increases inward with

pressure

All outer planets have many moons

Jupiter: at least 63 Saturn: at least 61 Uranus: at least 27 Neptune: at least 13

All outer planets have rings Thin disks of small particles of ice and rock Saturn’s rings are largest and most

complex

Scientists are constantly discovering new information about these planets and moons (using telescopes and space probes)

Largest and most massive planet

Mass is 2 ½ times more than all of the other planets combined

Thick atmosphere (hydrogen and helium)

Great Red Spot: Storm larger than Earth! Similar to a

hurricane Never ending 20,000 km long and

12,000 km wide

Dense core of rock and iron at its center Pressure is 30 times greater than on the

surface It has a thick mantle of liquid

hydrogen and helium

Jupiter’s largest moon. (Larger than Mercury)

Surface has dark and bright areas

Second largest Less ice Most craters

Not icy May have 300

active volcanoes

Ice Liquid water below the ice (possibly)

2nd largest planetThick atmosphere

(hydrogen and helium)

Made up of chunks of ice and rock going around Saturn

Some are kept in place from gravity of tiny moons

Titan (largest…larger than Mercury) Thick atmosphere (nitrogen and

methane) Some features formed from flowing

liquidMimas and Tethys: craters and

trenchesEnceladus: Ice and water erupt in

geysersPhoebe: ring of material found

4 times diameter of Earth

Looks blue-green due to methane in atmosphere

Rings

The 5 largest moons have icy, cratered surfaces

Tilted at an angle of about 90 degrees from the vertical

The tilt is due to an object hitting Uranus and knocking it on its side

Rotation = 17 hours

Similar to Uranus in size and color

Blue and cold Atmosphere

contains visible clouds

Interior is hot (forming clouds and storms at the surface)

Great Dark Spot (about the size of Earth) Scientists think it

is probably a giant storm that lasted a short period of time

13 moonsTriton (largest)Thin atmosphereNitrogen ice over south pole