Astronomy Ch. 14 Jupiter

Gas Giants

Jupiter and Saturn

Icy Giants

Uranus and Neptune

The outer planet + pluto characteristics

• Much larger than terrestrial planets

• thick atmospheres, mostly H and He

• No solid surfaces

• Strong atmospheric circulation

• cloud belt patterns

• Ring systems

• Multiple satellites

Belt Zone Circulation

• Clouds form dark belts and light zones that circle the planet

• More distinct on Jupiter and Saturn than Uranus and Neptune

Planets so lateness

How much is an object flattened at the pole

What causes Oblateness

• High rotation speeds

• mostly liquid interior

• large size

• small core

Regular Satellites

• Large and orbit close to parent planet

• Low inclinations to planets equator

• Moves in prograde direction

Irregular Satellites

• Smaller than regular satellites, generally far from parent planet

• Usually have high inclined orbits

• Sometimes have retrograde motion (opposite to parent planet)

• Tend to be captured objects

Jupiter

• First giant planet in solar system

• largest and most massive

• Contains almost ¾ of all planetary matter in the solar system

• fastest rotating planet

Jupiters Interior

• Mostly liquid hydrogen containing small amounts of heavier elements

• Pressure and temperature are higher than critical point for H

• No difference between gaseous and liquid H

• Radiates 1.7 times more energy than it receives from the Sun

Jupiters Magnetic Field

Large intense magnetic field, 14x that of Earth

Jupiters atmosphere

• No surface

• Hydrogen rich, clouds confined to a shallow layer

• cloud layers located at certain levels within atmosphere

• Belt zone circulation is driven by high and low pressure areas related to those on earth

• Large spots in clouds: circulating storms that remain stable for centuries

Jupiters great red spot

• Largest storm in the solar system

• As big as 2-3 Earths

• Ongoing since 1655

History of Jupiter

• Formed from cold gas in the outer solar nebula, where ices could condense

• Grew rapidly and became massive enough to capture and retain H and He gas

• Rapid rotation and outward flow of heat drives dynamo effect to produce very strong magnetic field that traps solar wind particles and makes auroras

• Rapid rotation and large size produced belt-zone circulation

• Large spots appear to be cyclonic disturbances

• Dust from meteorite impacts onto inner moons was trapped to form ring

Jupiters Moons

• Nearly 60 moons

• Most are captured asteroids

• 4 main big moons: Galilean Moons

Galilean Moons

1. Ip

2. Europa

3. Ganymede

4. Callisto

Jupiters strong gravitational field shapes its moons by:

• Tidal Heating: Internal heat due to friction caused by motions inside the moons

• Focused asteroids on it, so moons closer to jupiter receive more impacts

Callisto

• Dark surface, heavily pocketed with craters

• No metallic core, never differentiated to form core and mantle

• Layer of salty liquid water roughly 10 km thick about 100 km below it’s icy surface

Ganymede

• Largest moon in the solar system

• 1/3 of surface is old, dark and cratered; the rest marked by parallel grooves

Europa

• Density similar to earths moon

• Mostly rock and metal, with a surface of ice

• surface is active and erases craters almost as fast as they form

• thought to have twice as much water as oceans on earth below ice surface

Ip is characterized by

• body with the most volcanic activity in the solar system

• activity powered tidal interactions with jupiter

Jupiters rings

• Very dark and reddish

• Made of rock

• Particles orbit inside Roche Limit

Roche Limit

Distance below which a planets tidal force is stronger than moons gravity to held material together

• Distance < Roche Limit = rocks can’t stick together to form moons

• Distance > Roche Limit = rocks stick together and form moons