AST - Lecture 18: Jovian Planets and Moons

Terrestrial Planets

• Mostly heavy elements

• Mostly solid with thin or no atmosphere

• Low masses

• Spin slowly 

• No rings

• Few or nor no moons

Interior of Jupiter

• weight of everything above compresses the lower levels in a planet 

• With enough pressure, hydrogen can turn from a gas to a liquid to a metal

• Liquid and solids inside Jupiter

• Rocky core

• Metallic hydrogen

• Molecular hydrogen (second outermost layer)

• Upper atmosphere (outermost layer)

• Diluted core with enriched envelope

• Medium size planet smashed into Jupiter

• Stirred the dilute core

Jupiter Atmosphere

• complex clouds and stable storm

• Winds up to 500 km h

• Wind bands about. 3000 km thicK

Jupiter Clouds

• temperature and pressure varies as you enter

• Different molecules form clouds at different temperatures

• Ammonia clouds are white

• Ammonium hydrosulfide clouds are orange

• Different depths for different elements to condense and form clouds to form 

• Red bands are lower altitude clouds which are warmer and brighter

• White bands are higher altitude which are cooler and less bright

Saturn

• Second largest planet in the solar system

• 3.3x times less massive than Jupiter but close to the same size

• Structure much like Jupiter

• Many rings

• Tons of moons, 82 have names

What does Saturn have at its North Pole

It has a hurricane at the centre of a hexagon-shaped pole

Saturn’s Rings

The diameter of the rings is over 260,000 KM but arre only 0.1km thick

Do Jupiter/Uranus/Neptune have rings?

Yes but barely visible

uranus

• Ice giant

• Coldest planet

• Small rocky core

• Thick water, ammonia and methane mantle

• Thick H₂/He atmosphere

• Rotation axis tilted 98 degrees

• Thin rings and lots of moons

Neptune

• Furthest planet from the Sun

• Structure very similar to Uranus

• Rotation axis tilted 28 degrees

• More surface features than Uranus

• Strongest winds in solar system (2,100 KPH)

What are the interiors of Uranus and Neptune Like

• Composed of hydrogen, helium, methane gas

• Mantle is composed of water, ammonia, and methane ices

• Core is made of Rock and iCes

• Called Ice-giants

Features of Terrestrial Planets?

• Mostly hevy elements (C, Si, Fe, Ni, O)

• Mostly solid with thin or no atmosphere

• Low masses

• Spin slowly

• No rings

• Few or no Moons

Features of Jovian Planets

• Mostly hydrogen and Helium

• Thick layer of gas transition to liquid, then solid

• High masses

• Spin quickly

• All have rings

• Dozens of moons

Io

• Moon of jupiter

• Most geologically active object in the solar systrem

• Around the same size as the Earth’s moons

Europa

• Moon of Jupiter

• Surface covered with uncratered ice

• Smaller than the Earth’s moons

• There may be a huge ocean beneath the surface

Ganymede

• Moon of Jupiter

• Little larger than the Earth’s moons

• Surface includes some cratering, along with ancient geological activity

Callisto

• Moon of Jupiter

• A little smaller than Ganymede

• Surface is very heavily cratered

Titan

• Saturn’s largest moons

• Surface features hidden by thick clouds

• Titan has an atmosphere

• Has changing coastlines

What is the surface of Titan Like

• Pressure is 1.5 ATM

• 90% nitrogen

• It has lakes and weather

• 0% oxygen

• Surface made of ice

• Temperatures reach -180C

Iapetus

• Moon of Saturn

• Very old cratered surface

• Mostly made of Ices

• White is the natural colour (probably)

• Brown is a thin layer

• Giant ridge along the equator

Rhea

• Moon of Saturn

• Heavy cratered ball of ice

Enceladus

• One of the most reflective objects in the solar system

• Some parts are cratered and some are not

  • Active methane geysers

Hyperion

• Moon of saturn

• Made mostly of wate rice

• Heavily crated

• Dark amterial in bottom of Craters

• Very porous - 40% empty space

Miranda

• Moon of Uranus

• Some craters

• High ice content

• Strange geological features

Triton

• Moon of Neptune

• -235 C temperature

• Surface is mainly frozennitrogen

• Almost no atmosphere

• Geologically active (but water and ammonia)

• Orbits Neptune backwards

• Probably a captured dwarf planet