The Solar SystemThe Solar System

Solar Nebular TheoryInner PlanetsOuter Planets

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Solar Nebular TheorySolar Nebular Theory

Leading theory on the origin of our Leading theory on the origin of our solar solar systemsystem – not to be confused with the Big – not to be confused with the Big Bang Theory (origin of the universe)Bang Theory (origin of the universe)

Solar system began with the development of Solar system began with the development of the Sun – the only star in our solar systemthe Sun – the only star in our solar system

Outcome is a Outcome is a disk shapeddisk shaped system of the Sun system of the Sun surrounded by 8 planets, their moons, surrounded by 8 planets, their moons, meteors, asteroids and cometsmeteors, asteroids and comets

All planets and their moons are situated in All planets and their moons are situated in the disk on basically the the disk on basically the same planesame plane

Solar System Birth – Solar System Birth – What it Might Look LikeWhat it Might Look Like

Gas and dust in a Gas and dust in a nebula collapsing nebula collapsing due to gravity and due to gravity and creating a star…creating a star…

Swirling debris left Swirling debris left over after the over after the collapse…will collapse…will

become planets as become planets as time passestime passes

Solar Nebular Solar Nebular TheoryTheory

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Solar Nebular TheorySolar Nebular Theory

Solar System Birth - Large cloud of dust and gas collapse to form dense core – begins to spin and flatten into a disk

Proto-Sun Forms - Nebula’s densest part attracts more gas and dust – getting larger and hotter

Small Bodies Form - Particles stick together into fragments called planetesimals (building blocks of planets)

Solar Nebular TheorySolar Nebular Theory

Proto-Planets Form - Planetesimals clump together to form larger bodies called proto-planets

Planets Emerge - Sun becomes a star and its radiation blows away most leftover dusty gas, leaving behind 8 planets & moons

The Sun and eight* PlanetsThe Sun and eight* Planets

•My Very Excellent Mother Just Served Us Nachos

• Mercury• Venus• Earth• Mars

• Jupiter• Saturn• Uranus

• Neptune

The Inner PlanetsThe Inner PlanetsClick below for video clip

The Inner PlanetsThe Inner Planets• Terrestrial Planets – made of rock with

cores of iron• Much smaller than the gas giants• Dense• Planets’ surfaces have evidence of meteor

impacts – craters

MercuryMercury• Moves faster around the

sun than any other planet. (Named by the Romans after the fleet-footed messenger of the gods because of its speed)

• The closest planet to the Sun

• The surface of Mercury is badly scarred with craters badly scarred with craters due to the constant bombardment of meteorites.

• No atmosphereNo atmosphere – so really cold at night

• Ice can be found in shadows Ice can be found in shadows of deep cratersof deep craters

• Rank in size – 8thRank in size – 8th

VenusVenus• Often called Earth’s sister

planet – close to the same size and has similar composition as the Earth

• Venus has a thick atmosphere of carbon dioxide – causes greenhouse effect which traps immense heat and creates immense pressure

• Has the highest average surface temperature, as much as 475° C (900 ° F) due to greenhouse effect

• Atmosphere is so thick that we do not know what the surface is like without radar technology

• Size Rank – 6th

EarthEarth• The only planet to have The only planet to have water in all water in all

three phases – ice, liquid, water vaporthree phases – ice, liquid, water vapor• Nitrogen gas dominates the atmosphereNitrogen gas dominates the atmosphere• Silicon and oxygen dominate the crustSilicon and oxygen dominate the crust• Size Rank – 5Size Rank – 5thth (largest inner planet) (largest inner planet)• Will learn lots more later!!!Will learn lots more later!!!

MarsMars

• “Red Planet” due to iron oxide (rust) in the crust

• Has the largest volcano in the solar system – Olympus Mons – (4 times larger than Earth’s tallest mountain - Mt. Everest)

• Has polar ice caps and ice frozen under the surface

• Deep canyons are evidence that water once flowed on Mars

• Size Rank – 7th

How Large are Martian How Large are Martian Volcanoes?Volcanoes?

As large as some states

Probes to Mars

• http://www.space.com/12568-opportunity-nears-endeavor-crater-7-years-roving.html

The Boundary LineThe Boundary Line* Asteroid Belt* Asteroid Belt **

• Rocky bodies that orbit the Sun between Mars & Jupiter

• Natural Boundary between the inner planets and the outer planets

The Outer PlanetsThe Outer Planets“Jovian Planets”“Jovian Planets”

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For Size For Size ComparisonComparison

The Outer PlanetsThe Outer Planets“Jovian Planets”“Jovian Planets”

• Known as the “Gas Giants” or Jovian Planets• Very large planets• Made of mostly gas and dust• Pluto was the exception – more similar to

inner planets – small and solid.

JupiterJupiter• The largest planet• Predominantly gas –

90% hydrogen, 10% helium

• Has the Great Red Spot – a giant storm

• Has the largest moon in the solar system – Ganymede (larger than Pluto and Mercury)

• Has a moon that is volcanically active – Io

• Size Rank – 1st

SaturnSaturn• Another gas planet -

Density is so low – it could float on water

• Has the widest array of rings – made of gas, dust and ice

• Has 2nd largest moon – Titan (has nitrogen atmosphere like Earth)

• Size Rank – 2nd

UranusUranus• Revolves around

the sun like a spinning wagon wheel – axis is tilted on its side

• Has a blue/green color due to methane in the atmosphere

• Size Rank – 3rd

NeptuneNeptune• Another gas

planet• Methane in the

atmosphere gives it the blue-green color

• Size Rank – 4th

PlutoPluto

• Now called a “dwarf planet” by astronomers

• Has an eccentric orbit – sometimes coming closer to the Sun than Neptune

• Made mostly of rock and ice (unlike the other outer planets)

As compared to the U.S.

How Small is Pluto?

Pluto’s moon - Charon

Asteroids, Comets, Asteroids, Comets, MeteorsMeteors

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AsteroidsAsteroids• Asteroids - small to

large solid objects orbiting the sun usually between Mars and Jupiter…possibly left over debris that never joined up with other planets in the beginning.

• Some get bumped out of orbit and can slam into planets.

CometsComets• Comets – balls of

ice, dust and gas with a streaming tail pointing away from the sun (solar wind blows it)

• many comets reside in the Kuiper Belt or further out in the Oort Cloud.

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Meteor Meteor ShowerShower

• MeteorsMeteors – aka “shooting stars” - debris that burns up in Earth’s atmosphere

• MeteoroidsMeteoroids – debris moving through space

• Meteorites Meteorites – debris that hits Earth’s surface – creating craters

• DebrisDebris is generally leftover from comets’ tails