A Tour through the A Tour through the Solar SystemSolar System

The Inner PlanetsThe Inner Planets

Include Mercury, Venus, Earth, Include Mercury, Venus, Earth, and Marsand Mars

Also known as terrestrial planets Also known as terrestrial planets (terra means earth in Latin)(terra means earth in Latin)

All terrestrial planets are small, All terrestrial planets are small, dense, and have rocky surfaces.dense, and have rocky surfaces.

MercuryMercuryNamed for the Roman messenger god Named for the Roman messenger god

(Greek - Hermes)(Greek - Hermes) Smallest terrestrial Smallest terrestrial

planet (diameter is planet (diameter is 4,879 km)4,879 km)

Surface is covered Surface is covered by plains and by plains and craterscraters

Has no atmosphere Has no atmosphere and no moonsand no moons

Has the greatest Has the greatest temperature range temperature range of any of the of any of the planets: Day: 430°C planets: Day: 430°C Night: - 170°CNight: - 170°C

VenusVenusNamed for the Roman goddess of love and Named for the Roman goddess of love and

beauty (Greek - Aphrodite)beauty (Greek - Aphrodite) Close to the size of earth (Diameter is 12,104 Close to the size of earth (Diameter is 12,104

km)km) Surface is very volcanic and has many plains Surface is very volcanic and has many plains

covered in flowing lavacovered in flowing lava Atmosphere is so thick it is considered one Atmosphere is so thick it is considered one

giant cloud. The air pressure is 90 times giant cloud. The air pressure is 90 times earth’s. Air is mostly carbon dioxide. earth’s. Air is mostly carbon dioxide. Atmosphere traps in enough heat to melt Atmosphere traps in enough heat to melt lead (460°C), making it the hottest planet).lead (460°C), making it the hottest planet).

No moonsNo moons Venus takes longer to rotate on its axis than Venus takes longer to rotate on its axis than

it does to revolve around the sun. This it does to revolve around the sun. This makes its day longer than its year.makes its day longer than its year.

EarthEarthOnly Planet Name Not Derived from Only Planet Name Not Derived from

MythologyMythology Diameter is 12,756 Diameter is 12,756

kmkm Only planet that has Only planet that has

liquid water on the liquid water on the surface. The surface surface. The surface is solid rock with is solid rock with many volcanoesmany volcanoes

Only atmosphere rich Only atmosphere rich in oxygen (20%) Most in oxygen (20%) Most of the rest of the of the rest of the atmosphere is atmosphere is nitrogennitrogen

Has 1 moon Has 1 moon commonly called commonly called moon, but also moon, but also referred to as Luna referred to as Luna (Roman goddess of (Roman goddess of the moon)the moon)

Is in the exact Is in the exact position in the solar position in the solar system needed to system needed to support life. Any support life. Any closer to the sun and closer to the sun and it would be to hot; it would be to hot; farther, too coldfarther, too cold

MarsMarsNamed for the Roman god of war Named for the Roman god of war

(Greek – Ares)(Greek – Ares) Diameter – 6,794 kmDiameter – 6,794 km Surface is red because of rich amounts Surface is red because of rich amounts

of iron in the rocks. There are icecaps of iron in the rocks. There are icecaps at the poles. Many volcanoes dot the at the poles. Many volcanoes dot the surface but none are active.surface but none are active.

Atmosphere is 95% carbon dioxide.Atmosphere is 95% carbon dioxide. 2 moons (Phobos and Diemos)2 moons (Phobos and Diemos) Mars has a tilted axis and has seasons. Mars has a tilted axis and has seasons. Its largest volcano, Its largest volcano, Olympus MonsOlympus Mons is is

the size of Missouri and is 3 times taller the size of Missouri and is 3 times taller than Mt. Everest.than Mt. Everest.

The Outer PlanetsThe Outer Planets

Include Jupiter, Saturn, Uranus, and Include Jupiter, Saturn, Uranus, and NeptuneNeptune

Also known as the gas giants.Also known as the gas giants. Don’t have solid surfaces.Don’t have solid surfaces. Have a set of discs of small particles Have a set of discs of small particles

of ice and rock called ringsof ice and rock called rings

JupiterJupiterNamed for the Roman king of the gods Named for the Roman king of the gods

(Greek – Zeus)(Greek – Zeus) Largest planet Largest planet

(Diameter – 143,000 (Diameter – 143,000 km)km)

Surface is gaseous.Surface is gaseous. Atmosphere made up Atmosphere made up

of mostly hydrogen of mostly hydrogen and helium. The and helium. The Great Red Spot (GRS) Great Red Spot (GRS) is a storm twice as is a storm twice as large as Earth. Storms large as Earth. Storms on Jupiter never end. on Jupiter never end. GRS first observed in GRS first observed in the mid-1600’s.the mid-1600’s.

Rings are barely Rings are barely noticeable.noticeable.

63 known moons; Io, 63 known moons; Io, Europa, Ganymede, Europa, Ganymede, and Callisto are the and Callisto are the largest and were largest and were discovered by Galileodiscovered by Galileo

Its mass is 2.5 times Its mass is 2.5 times that of all the rest of that of all the rest of the planets. the planets.

Callisto Ganymede

Io

Europa

SaturnSaturnNamed for the Roman god of Named for the Roman god of

agriculture (Zeus’ father) (Greek – agriculture (Zeus’ father) (Greek – Cronus/Kronos)Cronus/Kronos)

22ndnd largest (Diameter – 120,500 km) largest (Diameter – 120,500 km) Gaseous surfaceGaseous surface Atmosphere is primarily hydrogen Atmosphere is primarily hydrogen

and helium. Also has clouds and and helium. Also has clouds and stormsstorms

Rings are 250,000 km in diameter, Rings are 250,000 km in diameter, but only 1 km thick.but only 1 km thick.

34 known moons, Titan is the largest34 known moons, Titan is the largest Saturn’s density is less than water.Saturn’s density is less than water.

UranusUranusNamed for the Greek god of the Named for the Greek god of the

heavens (Chronus’ father, husband of heavens (Chronus’ father, husband of Gaia)Gaia) Diameter – 51,100 Diameter – 51,100

kmkm Gaseous surfaceGaseous surface Traces of methane in Traces of methane in

the atmosphere give the atmosphere give it the blue-green it the blue-green colorcolor

Rings go from north Rings go from north to southto south

At least 25 moons, At least 25 moons, names come from names come from writings of writings of Shakespeare and Shakespeare and Alexander PopeAlexander Pope

Uranus’ axis is Uranus’ axis is tilted 90°. This tilted 90°. This causes a causes a “north/south” “north/south” rotation instead of rotation instead of the normal the normal “east/west” “east/west” rotation.rotation.

NeptuneNeptuneNamed for Roman god of the sea Named for Roman god of the sea

(Greek – Poseidon)(Greek – Poseidon) Diameter – 49,500 kmDiameter – 49,500 km Gaseous surfaceGaseous surface Blue gases fill the atmosphere. White Blue gases fill the atmosphere. White

and dark-colored clouds dot the sky.and dark-colored clouds dot the sky. Rings are barely noticeable.Rings are barely noticeable. 13 moons, largest is named Triton.13 moons, largest is named Triton. Neptune had a huge storm called the Neptune had a huge storm called the

Great Dark spot, but it didn’t last. Great Dark spot, but it didn’t last. The planet is actually sinking, causing The planet is actually sinking, causing

the core to heat up, which results in the core to heat up, which results in clouds.clouds.

Why Pluto Isn’t a PlanetWhy Pluto Isn’t a Planet

It doesn’t meet the third part of the It doesn’t meet the third part of the definition of a planet:definition of a planet:

1.1. Must orbit around the sunMust orbit around the sun

2.2. Must have a nearly round shapeMust have a nearly round shape

3.3. Must have cleared the area around Must have cleared the area around it so that no competing celestial it so that no competing celestial bodies are around (Charon is a bodies are around (Charon is a competing body that wasn’t cleared)competing body that wasn’t cleared)

PlutoPlutoNamed for the Roman god of the Named for the Roman god of the

underworld (Greek – Hades)underworld (Greek – Hades) Diameter – 2,400 Diameter – 2,400

km, smaller than km, smaller than the moon, Io, the moon, Io, Europa, Ganymede, Europa, Ganymede, Callisto, Titan, and Callisto, Titan, and TritonTriton

Rocky surfaceRocky surface No atmosphereNo atmosphere 1 moon – Charon 1 moon – Charon

(Greek figure who (Greek figure who ferried people to ferried people to the underworld)the underworld)

Orbit lasts 248 earth Orbit lasts 248 earth years. years.

At times during the At times during the orbit Pluto is orbit Pluto is actually closer to the actually closer to the sun than Neptune. sun than Neptune.

As of August 24, As of August 24, 2006 Pluto is 2006 Pluto is considered a “dwarf considered a “dwarf planet.”planet.”

Other Dwarf PlanetsOther Dwarf Planets

Eris – largest dwarf Eris – largest dwarf planet, has 1 moon planet, has 1 moon (Dysnomia)(Dysnomia) Located in the Kuiper Located in the Kuiper

Belt (Out past Pluto)Belt (Out past Pluto) Ceres – smallest dwarf Ceres – smallest dwarf

planetplanet Located in the asteroid Located in the asteroid

belt (between Mars and belt (between Mars and Jupiter)Jupiter)

Other Dwarf PlanetsOther Dwarf Planets

MakeMake was named a dwarf MakeMake was named a dwarf planet in June of 2008.planet in June of 2008.It’s the 3It’s the 3rdrd largest dwarf planet. largest dwarf planet.It is located in the Kuiper Belt, It is located in the Kuiper Belt,

where Eris is located.where Eris is located.HaumeaHaumea

It’s the 4It’s the 4thth largest dwarf planet. largest dwarf planet.2 moons – Hi’iaka and Namaka2 moons – Hi’iaka and NamakaLocated in the Kuiper BeltLocated in the Kuiper Belt