Chapter 4A Family of Planets
4.1 The Nine Planets
Measuring distancesAstronomical units (AU) = the distance the earth is from the sun
Light-minutes = 18,000,000 kmThe sun is 8.3 light minutes away
4.2 The Inner Planets
called terrestrial planet● rocky and dense● Mercury, Venus, Earth, Mars
Mercury
Fun facts:Slow rotation--A day lasts 59 day● rotation periodYou only weigh 38% of weight hereA year is 88 days● period of revolution
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Venus
Fun facts:slightly smaller than earthrotates opposite direction than earth
(sun rises in west)dense atmosphere (90x pressure)464oC surface temp
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Earth
Perfect distance from sun to have liquid water
We know fun facts:a year = a yeara day = a day etc...
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Mars
Most studied: Viking 1 and Viking 2Cold (-13oC to -77oC)● thin atmosphere and far from sun● no liquid water, pressure so low, it boils
away● ice caps and volcanoes● Weight is also 38% of earth
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4.3 The Outer Plantes
Large and composed of gas● Jupiter, Saturn, Uranus, Neptune and Pluto
(Pluto is small, dense, and rocky)
JupiterFun facts
Largest PlanetHigh pressure solidifies gasRed spot is 400 year old storm
3x the size of the earth
It is so hot, it radiates more energy than it collects from the sunyou weight 236% of your weight here (2.36x)
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Saturn
Second largest planetMostly Hydrogen and HeliumMay still be forming!Rings made of icy particles between a few cm to several m bigReleases heat
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Uranus
mostly Hydrogen and Methanetipped over to 90o angle Weigh less than earth (89%)
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NeptuneLooks bluemostly Hydrogen and Methanetipped over to 90o angle Releases heat
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Pluto
Half the size of MercuryHas one moon, CharonStill classified as planet, though some challenge
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4.4 Moons
satellites--bodies that revolve around larger bodies
Our moon, also called Luna,
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The surface of the moon
Bodies with no atmosphere preserve a record of impact craters
Can help identify age
Phases of the Moon
Moons continual changing appearance
Waxing: apparently getting largerWaning: apparently getting smaller
Eclipses
When the shadow of one celestial body falls on another
Lunar eclipse
Moon looks red because of bending light around earths atmosphere
The moons of other planets
Mars has 2Jupiter has dozens, 4 main ones
Io, Europa, Callisto and GanymedeSaturn has dozens
Titan is largestUranus has several
Miranda has strange features
Neptune has severalone large called Triton
Pluto has 1Charon
4.5 Small Bodies in the Solar System
Cometssmall body of ice, rock,
and cosmic dust“dirty snowballs”
Comet tailsgas and dust released by sun’s heation tail: electrically charged particles
Asteroids
● small rocky bodies that revolve around the sun
An asteroid beld exists between Mars and Jupiter
Types of Asteroids
Dark reddish brown on outside
Light gray on inside with stoney or metalic
Three asteroids:
Meteoroids: relatively small, rocky body that travels in space
Meteorite: meteroid that reaches Earth’s surface without completely burning up
Meteor: a bright streak of light that results when a mereoroid burns up in the atmosphere
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Interpreting GraphicsUse the diagrams below to answer the questions that follow.
Standardized Test PreparationChapter J4
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1. According to the information above, which planet has the oldest surface?
A planet A
B planet B
C planet C
D planet D
Standardized Test PreparationChapter J4
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1. According to the information above, which planet has the oldest surface?
A planet A
B planet B
C planet C
D planet D
Standardized Test PreparationChapter J4