Formation of the Solar Formation of the Solar SystemSystem

Chapter 3

A Solar System is BornA Solar System is BornSection 1 VocabularyNebulaSolar Nebula

The Solar NebulaThe Solar Nebula

Clouds-NebulaMixtures of mainly

gas (helium and hydrogen) and dust made of elements such as carbon and iron

Can be seen when nearby stars illuminate

GRAVITY AND PRESSURE

Gravity Pulls Matter Gravity Pulls Matter TogetherTogether

Made of matterHeld together by

the force of gravity

A lot of space between the particles◦ Less dense than air◦ Gravitational

attraction=weak Strong enough to

keep from drifting

Pressure Pushes Matter Pressure Pushes Matter ApartApart Relationship between

temperature and pressure Temperature-measure of

the average kinetic energy of the particles in an object◦ Energy of motion

Little kinetic energy- move slowly and temp. of cloud is low

A lot of kinetic energy- move fast and temp. of cloud is high

Sometimes crash into each other

In a nebula, outward pressure balances the inward gravitational pull and keeps the cloud from collapsing

Upsetting the BalanceUpsetting the Balance

Gravity and Pressure◦ Upset if two nebulas

collide or nearby star explodes

Compress small regions of a nebula called globules ◦ Gas clouds◦ Become so dense they

contract under their own gravity

When it collapses inward the temp. increases and the stars can form

Solar Nebula

How the Solar System How the Solar System FormedFormed Collapse Took 10 million years for

the solar system to form Denser and the

attraction between the gas and dust particles increased

Center of the cloud became very hot and dense

Began to rotate slowly around the center

Helped balance the pull of gravity

Flattened into a rotating disk

All planets

From Planetesimals to From Planetesimals to PlanetsPlanets

Circled the center of the solar nebula◦ Some collided◦ Stuck together to form

golf-sized bodies Drifted into the solar

nebula◦ Made them grow bigger

Largest of the bodies are called planetesimals◦ Small planets

Some are part of the cores of current planets

Some collided to form craters

Gas Giant or Rocky Gas Giant or Rocky Planet?Planet? Largest formed near

the outside of the rotating solar disk◦ Hydrogen and Helium

Far enough to attract nebula gases

Grew to huge sizes and became gas giants

Closer to the center temp. were to hot for gases to remain◦ inner planets◦ Rocky material

The Birth of a StarThe Birth of a Star

As they were forming other matter was traveling to the center

Nuclear fusion Released huge

amounts of energy and created enough outward pressure to balance the inward pull of gravity

Sun was born

The Sun: Our Very Own The Sun: Our Very Own StarStarSection 2 Vocabulary

◦Nuclear Fusion◦Sunspot

The Structure of the SunThe Structure of the SunNot a solid

surfaceLooking at the

sun you seeing the outer atmosphere

Made of many layers

Energy Production in the Energy Production in the SunSun

Shining on Earth for about 4.6 billion years

Sun burned fuel to generate its energy◦ Amount of energy

released by burning would not be enough to power the sun

◦ It would only last 10,000 years.

Burning or Shrinking?Burning or Shrinking?Burning would not lastStarted thinking that

gravity was causing the sun to shrink slowly◦ Would release enough

energy to heat the sun◦ Not enough power◦ Would only last 45

million years◦ Fossils-65 million years

More powerful than gravity

Nuclear FusionNuclear FusionBeginning of 20th

century-Einstein showed that matter and energy are interchangable

E=MC2

Tiny amounts of matter can produce a huge amount of energy

Nuclear Fusion-four hydrogen can nuclei can fuse to form a single nucleus of helium◦ Energy is produced◦ Sun gets its energy

Fusion in the SunFusion in the SunDuring normal

conditions◦ Never get close

enough to combine◦ Positively charged

In the sun◦ Temperature and

pressure are very high

◦ Have enough energy to overcome the repulsive force

◦ Hydrogen fuses into helium

Fusion in the SunFusion in the Sun

The energy produced in the center◦ Takes millions of years

to reach the sun’s surface

Radiative Zone- the energy passes from the core through a very dense region◦ So crowed that the light

and energy are blocked and sent in different directions

Convective Zone-gases circulate ◦ Gases carry the energy

upPhotosphere- visible

surface of the sun

Solar ActivitySolar ActivityEver-Changing PlaceThermal energy

moves from the sun’s interior by the circulation of gases in the convective zone.

Movement of energy- photosphere will boil and churn

Circulation+Sun’s rotation= magnetic field

SunspotsSunspotsMagnetic Field slows

down activity in the convective zone◦ Causes spots to be

cooler◦ Dark spots

Sunspots◦ Different size and

shape◦ 11 year cycle◦ Peak intensity then

decreases

Climate ConfusionClimate ConfusionSunspots can

affect earthPeriod of low

sunspot activity- low temperatures in Europa◦ Little Ice Age

More research is needed

Solar FlaresSolar FlaresMagnetic Fields can

also cause solar flaresRegions of extremely

high temperature and brightness that develop on the sun’s surface

Huge streams of electricity charged particles into the solar system◦ Sunspots◦ Interrupt radio

communications

The Earth Takes ShapeThe Earth Takes ShapeSection 3 Vocabulary

◦Crust◦Mantle◦Core

Formation of the Solid Formation of the Solid EarthEarth

Third planetMostly rock¾ waterProtective

atmosphere◦ Nitrogen◦ oxygen

Planetesimals collided and combined

First 10 million years

The Effects of GravityThe Effects of GravitySmall-irregular

shapePlanet gains more

matter-gravity increases

350 km-gravity becomes greater than the strength of the rock

Rock crushed by gravity and planet rounded

The Effect of HeatThe Effect of HeatChanging shape-heating

upCollisions of

planetesimals- energy of motion heated the planet◦ Radioactive material

Certain size- temperature rose faster than the interior could cool and rocky material melted

Still cooling◦ Volcanoes, earthquakes,

and hot springs◦ Helped form layers

How the Earth’s Layers How the Earth’s Layers FormedFormedOil and vinegarRock melted

◦ Denser materials sank (nickel and iron) and formed the core

◦ Less dense materials floated to the surface and formed the crust

How the Earth’s Layers How the Earth’s Layers FormedFormed

Crust- the thin outermost layer of the Earth◦ 5-100 km think◦ Low densities-

oxygen silicon and aluminum

Mantle-layer beneath the crust◦ Extends 2,900 km