OUTER PLANETS

LETS REVIEWName the four inner planets?What was there surface consisting of?

What name were the four inner planets known as? Hint starts with a T

Most of what astronomers know about outer planets have come from space probes

Compared to Earth some planets are huge

Jupiter is 11 times larger If Earth were a Chihuahua Jupiter

would be a Great Dane

four outer planetsJupiter, Saturn, Uranus, & Neptune

Do not have solid surfaceCalled Gas GiantsStronger gravitational forcePartly solid core

JUPITER

Most massive planetThick atmosphere of hydrogen and helium

Colorful bands of thick cloudsGreat Red Spot: ongoing storm

JUPITER’S MOONS 4 moons: Io, Europa, Ganymede, Callisto Are 4 largest Later have discovered many more Io

Covered with volcanoesLooks like giant pizza

EuropaIcy crust

GanymedeLargest, icy and partly covered with craters

CallistoIcy surface and every part covered with

craters

FOLDABLE5th planet from the sunLargest planetAtmosphere is made mostly of

hydrogen, helium, methane, and ammonia

Great Red Spot is a ongoing stormHas a ring systemFour large and 24 small moonsDay=9hours56minYear=12 years

SATURN

2nd largestSlightly smaller than Jupiter but with rings has greater diameter

Thick atmosphereContains clouds and storms

Only planet less dense then water

SATURN’S RINGS AND MOONSRings made of chunks of ice and rockHUNDREDS of ringsEach travel in their own orbit around

SaturnBroad and think like a cdRecently rings have been discovered

around other 3 gas giants but not as spectacular as Saturn's

Many moonsLargest called Titan: little light gets

through

FOLDABLE 6th planet from sun 2nd largest planet Thick atmosphere At least thirty moons

Largest moon: Titan (larger than Mercury) Less dense than water Has a ring system Day= 10 hours 39 min Year=29 years

URANUS

4 times the diameter of Earth but much smaller than Jupiter and Saturn

Twice as far from sun as Saturn so much colder

Looks bluish because of traces of methane in atmosphere

First new planet discovered since 1781Thought it might be a comet but when

studied had an orbit just beyond SaturnStarted major space exploration at the

time

In 1986 Voyager 2 sent back our only close up views

Only a few clouds Rotates in 17 hours Axis tilted at 90 degrees Rotates top to bottom instead of side to

side Astronomer think a object hit it and turned

it on its side 27 moons

5 largest icy, cratered surfaces, lava flows (comes from inside)

FOLDABLE 7th planet from sun Third largest Has ring system Axis at 90 degrees (rotates top to bottom) 27 moons Atmosphere of hydrogen, helium, methane,

and ammonia Methane caused bluish appearance Day=17 hours 14 min Year=84 years

NEPTUNE

30 times farther from Sun than Earth

Contains visible clouds1989 Voyager flew past and discovered Great Dark Spot(about size of Earth)

Probably a giant stormDidn’t last long, 5 years later it was gone

Other smaller spots seem to come and go

13 moonsLargest Triton

Near south pole covered with cap of ice, dark material erupts from underneath

Covered with ridges and crators

FOLDABLE8th planet from SunGreat Dark Spot: Storm as large as EarthHas high altitude windsAtmosphere made of hydrogen, helium,

methane, and ammoniaMethane causes blue colorHas 13 moons (Triton=largest)Has a ring systemDay=16 hours 6 minYear=165 years

PLUTO & CHARON

Solid surfacesLess than 2/3 size of Earth’s

moonMoon Charon is more than 1/2

size of Pluto considered double planet

Revolve once every 248 yearsAstronomers don’t know much

about themPluto discovered in 1930, Charon

in 1978

Is it really a planet?Many astronomers say it is too

smallSay it is just the largest of

thousands of objects revolving around the sun beyond Neptune

If astronomers had found these other objects before Pluto might not have called it a planet

FOLDABLE 9th planet from Sun Atmosphere is nitrogen, carbon monoxide,

and methane, Moon, Charon, half the size of Pluto Oval orbit sometimes puts it closer to the sun

than Neptune 248 days to revole Solid Surface