The Solar System: Inner The Solar System: Inner PlanetsPlanets

What is a planet?What is a planet? A A planetplanet is a body of matter that is a body of matter that

travels around a star in a fixed path travels around a star in a fixed path called an orbit.called an orbit.

Planets don’t give off their own Planets don’t give off their own light…they light…they reflectreflect the light of the the light of the Sun.Sun.

Planets are classified as inner Planets are classified as inner planets and outer planetsplanets and outer planetsInnerInner

MercuryMercury VenusVenus EarthEarth MarsMars

OuterOuterJupiterJupiterSaturnSaturnUranusUranus

NeptuneNeptune PlutoPluto

THE INNER PLANETSTHE INNER PLANETS A.K.A Terrestrial Planets- Earth LikeA.K.A Terrestrial Planets- Earth Like

All composed of a solid rock surfaceAll composed of a solid rock surface

If we had the proper technology, we If we had the proper technology, we could travel across these planets could travel across these planets collecting samplescollecting samples

MERCURYMERCURY

Mercury is the closest planet to the Mercury is the closest planet to the sun.sun.• Mercury is only about one-third the

size of Earth• It is smaller than any other planet except Pluto• Year lasts 88 days (revolution)• It takes 59 Earth days for one complete rotation

Lack of AtmosphereLack of Atmosphere Because it is so close to the sun, Because it is so close to the sun,

Mercury has no atmosphereMercury has no atmosphere Therefore, it has no weatherTherefore, it has no weather Temps. During the day can be 427 Temps. During the day can be 427

degrees Celsius (800 degrees F.) and degrees Celsius (800 degrees F.) and fall during the night to -170 degrees fall during the night to -170 degrees Celsius (-274 degrees F.)Celsius (-274 degrees F.)

Craters on MercuryCraters on Mercury

U.S. Space Craft, Mariner 10, flew past Mercury in 1975Landscape is covered with craters from material striking the planet

VENUSVENUS

Venus is the second planet from the sun Has a similar diameter, mass, and density as Earth- Thus Venus is known as Earth’s Twin! They differ in that Venus does not have oceans or human life Also, it’s temp. reaches 484 degrees Celsius (903 degrees F.) In 1975, two Soviet Space Craft landed on Venus and were destroyed within hours due to harsh atmospheric conditions

Way Too Much Atmosphere!Way Too Much Atmosphere!

Thick blanket of dense clouds high Thick blanket of dense clouds high up in the planet’s atmosphereup in the planet’s atmosphere

These clouds contain sulfuric acid These clouds contain sulfuric acid which gives them a yellowish colorwhich gives them a yellowish color

Beneath this cloud layer is a layer of Beneath this cloud layer is a layer of Carbon Dioxide GasCarbon Dioxide Gas

This gas is much denser than the This gas is much denser than the nitrogen and oxygen that makes up nitrogen and oxygen that makes up our atmosphere on Earthour atmosphere on Earth

DO YOU HAVE ANY IDEAS DO YOU HAVE ANY IDEAS WHY VENUS GETS SO HOT?WHY VENUS GETS SO HOT?

It’s so hot because……It’s so hot because…… Carbon Dioxide traps the heat and Carbon Dioxide traps the heat and

causes the greenhouse effect. It acts causes the greenhouse effect. It acts like the glass in a green-house and like the glass in a green-house and traps all the heat inside.traps all the heat inside.

More FactsMore Facts Sixth largest planetSixth largest planet It rotates opposite of all other It rotates opposite of all other

planets- clockwiseplanets- clockwise The Venusian day takes 243 Earth The Venusian day takes 243 Earth

DaysDays The Venusian year lasts 224 Earth The Venusian year lasts 224 Earth

DaysDays

Temperatures can reach 484 Temperatures can reach 484 degrees Celsius (903 degrees F.)!degrees Celsius (903 degrees F.)!

Highest temperature on Earth has Highest temperature on Earth has been 58 degrees Celsius (136.4 been 58 degrees Celsius (136.4 degrees F.)degrees F.)

RADAR pictureBlue=smoothBrown =rough

EARTHEARTH

Third Planet from the sunThird Planet from the sun Fifth Largest PlanetFifth Largest Planet Only planet known to support lifeOnly planet known to support life Surface contains 70% water and 30% Surface contains 70% water and 30%

landland Atmosphere is 78% nitrogen, 21% Atmosphere is 78% nitrogen, 21%

oxygen, and 1% argonoxygen, and 1% argon Water exists in all three states of matterWater exists in all three states of matter

It takes 24 hours to rotate around It takes 24 hours to rotate around the axis- which equals one daythe axis- which equals one day

It takes 365 days to revolve around It takes 365 days to revolve around the sunthe sun

It has one satellite- the moonIt has one satellite- the moon

MARSMARS

Mars is the 4Mars is the 4thth planet from the sun planet from the sun 228 million km from sun228 million km from sun Seventh largest planetSeventh largest planet In 1976 Viking 1 and Viking 2 probes In 1976 Viking 1 and Viking 2 probes

landed on mars to give us important landed on mars to give us important new information on the atmospheric new information on the atmospheric conditions and rugged landscapeconditions and rugged landscape

The Martian atmosphere is very thin, and solar winds carry it Away because Mars has a weak gravitational and magnetic field

The Martian soil is coated with a reddish compound also known as rust...can you guess what this compound would be?

Surface covered by rocks and soil

The surface of Mars is very cold: A high temp. may reach -20 degrees Celsius (-4 degrees F.) to a low of -140 degrees Celsius (-220 degrees F.)

Olympus MonsOlympus Mons Largest known volcano in the solar system

3 times taller than the tallest mountain on Earth

Base would stretch from Washington D.C. to Boston

Volcanoes are dormant or inactive

Valles MarinerisValles Marineris

Valles Marineris is Mars’ largest canyon. If placed on Earth,It would stretch from New York City to Los Angeles

Why is there no life on Why is there no life on Mars?Mars?

The Earth’s ozone layer absorbs The Earth’s ozone layer absorbs harmful UV rays from the sunharmful UV rays from the sun

Mars has no ozone. Mars has no ozone. It lacks the simplest molecules It lacks the simplest molecules

because they can’t survive the UV because they can’t survive the UV raysrays

Earth sounds pretty nice Earth sounds pretty nice right about now, doesn’t right about now, doesn’t

it?it?