The Outer Planets

The Outer Planets

Gas Giants

Outer Planets = Gas Giants

• The 4 outer planets are much larger and more massive than Earth

• They do not have solid surfaces

• Their size exerts a very strong gravitational force

• This force keeps gases from escaping and creates thick atmospheres

Outer Planets = Gas Giants

• High pressures inside the planets causes materials to actually be liquid

• Outer layers are extremely cold but inner layers are much warmer

• All gas giants have many moons and are surrounded by rings

• Some moons are small balls of rock and ice only 1km across, while others are larger than Mercury

• The rings are thin discs of small rock and ice particles

Jupiter - "Giant Planet"

• Largest and most massive planet

• Mass = about 2.5 times more than all other planets combined

• Composed mostly of hydrogen and helium

• Atmosphere contains the "Great Red Spot"

• This is a giant storm with winds similar to a hurricane on Earth

Jupiter contiuned...

• Possibly has a dense core of rock and iron

• Core is surrounded by liquid hydrogen

• Has at least 63 moons

• The 4 largest being Ganymede, Callisto, Io, and Europa

Saturn - "Ringed Planet"

• Second largest planet

• Atmosphere composed of hydrogen and helium

• North pole has strange hexagon shaped clouds

• Has the most complex set of rings

Saturn continued...

• From Earth, it appears to have 7 main rings but actually there is between 500-1000

• Saturn's largest moon, Titan, is the larger than Mercury and the only moon with a thick atmosphere

• Titan's atmosphere is composed mostly of nitrogen and methane

Uranus - "Ice Giant"

• Twice as far from the Sun as Saturn so it is MUCH colder

• Gets its blue-green color from methane in its atmosphere

• Has at least 27 moons

• Axis is rotated 97.9 degrees making it "roll" around the Sun

Neptune - "Windy Planet"

• A very cold, blue planet with visible clouds in the atmosphere

• Neptune's interior is still hot, releasing energy that rises and causes clouds and storms

• Once had a "Great Dark Spot" storm, similar to Jupiter

• Voyager 2 probe showed the largest moon, Triton, is covered in nitrogen ice

Multiple Choice

Gas Giants have solid surfaces.

• True

• False

Multiple Select

Which planets are Gas Giants?

• Venus

• Saturn

• Mars

• Pluto

• Neptune

Multiple Choice

Which planet rotates on its side?

• Jupiter

• Uranus

• Mercury

• Neptune

• Saturn

Multiple Choice

Which planet has a huge hurricane-like storm in its atmosphere?

• Neptune

• Saturn

• Jupiter

• Uranus

Multiple Select

What are the outer planet's rings made of?

• Rocks

• Lava

• Dead stars

• Ice