The Solar SystemThe Solar SystemA journey through our neighboring A journey through our neighboring

planetsplanets

Learning ObjectivesLearning Objectives

Analyze the size and scale of our solar Analyze the size and scale of our solar system.system.

Explain events in the formation of the solar Explain events in the formation of the solar system.system.

Compare the terrestrial (rocky) planets to Compare the terrestrial (rocky) planets to the Jovian (gaseous) planets.the Jovian (gaseous) planets.

Distinguish key characteristics of the Distinguish key characteristics of the planets and objects in our solar system.planets and objects in our solar system.

Scale of the Solar SystemScale of the Solar System The size of the solar The size of the solar

system is system is HUMONGOUS!HUMONGOUS!

Yet our solar system Yet our solar system is a tiny speck when is a tiny speck when compared to stars in compared to stars in our galaxy, which is our galaxy, which is only one of billions.only one of billions.

Scale of the PlanetsScale of the Planets

The Sun makes up 99.86% of The Sun makes up 99.86% of the entire mass of the entire the entire mass of the entire solar system.solar system.

Figure 2 from page 646 shows Figure 2 from page 646 shows the scale size of the planets. the scale size of the planets. Look at how tiny our planet is Look at how tiny our planet is compared to the gas giants compared to the gas giants and especially the sun!and especially the sun!

The The NEBULAR NEBULAR THEORY THEORY provides provides an explanation of an explanation of how about 5 billion how about 5 billion years ago our solar years ago our solar system was formed.system was formed.

See figure 3, page See figure 3, page 647.647.

ASTRONOMICAL UnitsASTRONOMICAL Units Astronomers use astronomical Astronomers use astronomical

units, AU, to measure how far units, AU, to measure how far planets are from each other.planets are from each other.

AU is the distance from the AU is the distance from the Earth to the sun - a whopping Earth to the sun - a whopping 150,000,000km150,000,000km

It would take 17 years to travel It would take 17 years to travel this far in a jet going the this far in a jet going the speed of a bullet 1,000km/hr!speed of a bullet 1,000km/hr!

The Sun: OUR STARThe Sun: OUR STAR The sun is the biggest, The sun is the biggest,

brightest, and hottest brightest, and hottest object in the solar object in the solar system.system.

Diameter= 1.4 million Diameter= 1.4 million kmkm

Made of about 70% Made of about 70% hydrogen and 28% hydrogen and 28% helium.helium.

Could hold a million Could hold a million Earth’s inside.Earth’s inside.

MercuryMercury Mercury is solid and Mercury is solid and

is covered with is covered with craters.craters.

Diameter= 4878kmDiameter= 4878km Mercury has almost Mercury has almost

no atmosphere.no atmosphere. Mercury is the Mercury is the

smallest true planet.smallest true planet.

VenusVenus Venus is the sixth Venus is the sixth

largest planet. It’s about largest planet. It’s about three-fourths the size of three-fourths the size of earth.earth.

Diameter= 12,104kmDiameter= 12,104km The surface is rocky The surface is rocky

and very hot. The 97% and very hot. The 97% COCO22 atmosphere atmosphere

completely hides the completely hides the surface and traps the surface and traps the heat.heat.

EarthEarth Earth is the fifth largest planet and the third from the sun.Earth is the fifth largest planet and the third from the sun. A terrestrial planet with an atmosphere made of 71% Nitrogen and A terrestrial planet with an atmosphere made of 71% Nitrogen and

28% Oxygen28% Oxygen Diameter= 12,756kmDiameter= 12,756km Liquid water covers 71 percent of the Earth’s surface.Liquid water covers 71 percent of the Earth’s surface. The Earth has one moon.The Earth has one moon.

Moon: LunaMoon: Luna

MarsMars Mars is the fourth Mars is the fourth

rocky planet from the rocky planet from the sun.sun.

Diameter= 6,794kmDiameter= 6,794km Mars has a thin Mars has a thin

atmosphere that atmosphere that contains mostly contains mostly carbon dioxide.carbon dioxide.

Mars has two small Mars has two small moons.moons.

Moons of MarsMoons of Mars

PhobosPhobos

DeimosDeimos

Let’s ReviewLet’s ReviewHow was the solar system formed?How was the solar system formed?What is an astronomical unit and why is it What is an astronomical unit and why is it

used?used?What are the name of the terrestrial What are the name of the terrestrial

planets?planets?Which planets have no moons?Which planets have no moons?

Jupiter: The Giant PlanetJupiter: The Giant Planet

The largest of the The largest of the planets. Can hold planets. Can hold 1,300 and the rest of 1,300 and the rest of the planets.the planets.

Diameter= 143,884kmDiameter= 143,884kmHas hydrogen-helium Has hydrogen-helium

atmosphereatmosphere

Jupiter’s Red SpotJupiter’s Red Spot The Great Red Spot, a The Great Red Spot, a

huge storm of swirling huge storm of swirling gas that has lasted for gas that has lasted for hundreds of years and hundreds of years and is the size of 3 Earths.is the size of 3 Earths.

Jupiter does not have Jupiter does not have a solid surface. The a solid surface. The planet is a ball of liquid planet is a ball of liquid surrounded by gas.surrounded by gas.

Moons of JupiterMoons of Jupiter

Jupiter has four large Galilean moons, Jupiter has four large Galilean moons, twelve smaller named moons and over 40 twelve smaller named moons and over 40 irregular satellites for a total of 63 moonsirregular satellites for a total of 63 moons

We’ll take a look at the four large Galilean We’ll take a look at the four large Galilean moons which were first observed by moons which were first observed by Galileo Galilei in 1610. Galileo Galilei in 1610.

IoIo

Io is the fifth moon of Io is the fifth moon of Jupiter. It’s the third Jupiter. It’s the third largest of Jupiter’s largest of Jupiter’s moons.moons.

Io has hundreds of Io has hundreds of volcanic calderas. volcanic calderas. Some of the volcanoes Some of the volcanoes are active.are active.

EuropaEuropa Europa is the sixth of Europa is the sixth of

Jupiter’s moons and is Jupiter’s moons and is the fourth largest.the fourth largest.

It is slightly smaller than It is slightly smaller than the Earth’s moon.the Earth’s moon.

The surface strongly The surface strongly resembles images of sea resembles images of sea ice on Earth. There may ice on Earth. There may be a liquid water sea be a liquid water sea under the crust.under the crust.

Europa is one of the five Europa is one of the five known moons in the solar known moons in the solar system to have an system to have an atmosphere.atmosphere.

GanymedeGanymede

Ganymede is the Ganymede is the seventh and largest of seventh and largest of Jupiter’s known Jupiter’s known satellites.satellites.

Ganymede has Ganymede has extensive cratering extensive cratering and an icy crust.and an icy crust.

CallistoCallisto

Callisto is the eighth of Jupiter’s known satellites Callisto is the eighth of Jupiter’s known satellites and the second largest.and the second largest.

Callisto has the oldest, most cratered surface of Callisto has the oldest, most cratered surface of any body yet observed in the solar system.any body yet observed in the solar system.

SaturnSaturn Saturn is the second largest planet and the sixth from the Saturn is the second largest planet and the sixth from the

sun.sun. Diameter= 120,536kmDiameter= 120,536km Saturn is made of materials that are lighter than water. If Saturn is made of materials that are lighter than water. If

you could fit Saturn in a lake, it would float!you could fit Saturn in a lake, it would float! Has 56 MoonsHas 56 Moons

Rings of SaturnRings of Saturn

Saturn’s rings are not Saturn’s rings are not solid; they are solid; they are composed of small composed of small countless particles.countless particles.

The rings are very The rings are very thin. Though they’re thin. Though they’re 250,000km or more in 250,000km or more in diameter, they’re less diameter, they’re less than one kilometer than one kilometer thick.thick.

UranusUranus

Uranus is the third Uranus is the third largest planet and the largest planet and the seventh from the sun.seventh from the sun.

Diameter= 51,118kmDiameter= 51,118km Uranus is blue-green Uranus is blue-green

because of the because of the methane in its methane in its atmosphere.atmosphere.

Has 27 moonsHas 27 moons

NeptuneNeptune

Neptune is the fourth Neptune is the fourth largest planet and the largest planet and the eight from the sun.eight from the sun.

Diameter= 50,530kmDiameter= 50,530km Like Uranus, the Like Uranus, the

methane atmosphere methane atmosphere gives Neptune its gives Neptune its color.color.

Has 13 moons.Has 13 moons.

PlutoPluto

Pluto is a dwarf planet Pluto is a dwarf planet and usually the and usually the farthest from the sun.farthest from the sun.

Pluto is the only Pluto is the only “planet” that has not “planet” that has not been visited by a been visited by a spacecraft.spacecraft.

Diameter= 2,300kmDiameter= 2,300km

Planet MovementsPlanet Movements

Move in an elliptical orbitMove in an elliptical orbit influenced by the sun’ gravityinfluenced by the sun’ gravity

Period of RevolutionPeriod of Revolution

the time it takes to go once around the sunthe time it takes to go once around the sunone year on Earth (365.25 days) one year on Earth (365.25 days) Mercury 88 days, Pluto 248 yearsMercury 88 days, Pluto 248 yearsWhy is the revolution period longer for Why is the revolution period longer for

farther planets?farther planets?

What keeps them there?What keeps them there?

Law of inertia - objects motion won’t Law of inertia - objects motion won’t change unless acted upon by an outside change unless acted upon by an outside force.force.

Won’t change speed or directionWon’t change speed or directionWhy do they curve?Why do they curve?Gravity pulls them toward the sunGravity pulls them toward the sun

What keeps them there?What keeps them there?

SUN

Inertia

Gravit

y

RotationRotation

Planets spin on their axesPlanets spin on their axesOne rotation is a dayOne rotation is a dayMercury 58 days, Jupiter 10 hoursMercury 58 days, Jupiter 10 hoursWhy do you think rotation is faster for Why do you think rotation is faster for

larger planets?larger planets?

Analyze ThisAnalyze This

What trend do you notice within this graph?What trend do you notice within this graph?

Analyze ThisAnalyze This

Notice the materials Notice the materials which make the which make the planets. planets. Which Which planets are more planets are more dense?dense?

Read page 648 to Read page 648 to learn how gravity also learn how gravity also influenced the influenced the structure and size of structure and size of the planets.the planets.

Other Space StuffOther Space StuffComets: chunks of dust and gas that Comets: chunks of dust and gas that

originate from the Oort cloud on the edge originate from the Oort cloud on the edge of the solar system. of the solar system.

Asteroids: chunks of planetlike material Asteroids: chunks of planetlike material floating in space mostly between Mars and floating in space mostly between Mars and Jupiter. Jupiter.

Other Space StuffOther Space Stuff

Meteor: the shooting star -the light you see Meteor: the shooting star -the light you see the skythe sky

Meteoroid: solid rocky objects circling the Meteoroid: solid rocky objects circling the sunsun

Meteorite: When a meteor hits the groundMeteorite: When a meteor hits the groundMost don’t reach the ground because they Most don’t reach the ground because they

burn up in the atmosphereburn up in the atmosphere