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Our Solar System

S8.D.3.1.1-3

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Universe

Galaxy

Infinity 2008 video

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)Milky Way Galaxy (Our Galaxy)

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• Universe All of the matter and energy that exists Everything (all of outer space)There are more stars in Universe than grains of sand in the world

• Galaxy collection of stars and nebula contains 100’s of billions of stars

Nebula cloud of dust and gas which condenses to form a new starVideo

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• Solar System- contains:(1) one star (sun)(2) planets, dwarf planets, moons(3) Asteroids, comets, meteoroids

NASA Planet Fact Site

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Solar System

• The Sun is Earth’s closest star• The Sun is the most massive body in our Solar System•The sun is an average-size star in the Milky Way Galaxy

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Nuclear Fusion

• Hydrogen atoms fuse to form helium atoms

• Lots of energy is given off in the process (7 forms of EM Radiation)

• H + H He + energy

How The Sun Produces Energy:

Opposite of Nuclear Fission

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What Happened To Pluto? in Aug. 2006 IAU (International Astronomical Union) changed the definition of a planet

PLANET• Orbits the Sun• Nearly Round • Clears its own orbital

path around the Sun

• Now have 8 planets

DWARF PLANET• Orbits the Sun• Nearly Round• Does not clear its own

path around the Sun

• 5 Dwarf Planets so far (hundreds more to come)

• Ceres, Pluto, Haumea, Makemake, Eris

Video clip

NASA Planet Fact Site

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Inner Planets vs Outer Planets

• Small and Rocky • Solid Surface• Low mass• High Density• Close to sun• Closely spaced orbits• Few moons (if any)• No rings• Terrestrial Planets• Mercury,Venus,Earth,Mars

• Large and Gaseous • No solid surface• High mass• Low Density• Far from sun• Separated orbits• Many moons• Many rings• Gas giants• Jupiter,Saturn, Uranus,

Neptune

Size of planets video clipSize of planets video clip #2

NASA Planet Fact Site

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Mercury• Surface resembles the moon’s

• No Moon or Atmosphere (very thin, hardly any) • Shortest Year (88 E days)Revolves faster than any other planet (107,000 mph) and has the shortest distance to travel around the Sun • Long DayRotates slowly takes 59 E. days

• Temperature Range (greatest of any planet)High = 800F Low = -274F*Days and nights are long, so it has lots of time to heat up and cool down.

NASA Planet Fact Site

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Venus• No Moon • Atmosphere• Very thick clouds made of CO2 and Sulfuric Acid • Atmospheric pressure is 91x greater than Earth’s• Severe Greenhouse Effect because of thick Carbon Dioxide• Hottest Planet @ 900 F• It rains Sulfuric Acid

• Day (Longest of any Planet) 243 E. Days

• Year 225 E. Days

**Day is Longer than a Year on Venus**

Venus rotates the opposite way

Video clip

NASA Planet Fact Site

Mars

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• The Red Planet, because of the iron oxide (rust) in its soil • Day= 24.5 hrs • Year= 1.9 Earth Years • Diameter = about ½ Earth

• No Liquid water today???, although it is thought to have had water in the past. Evidence of dried riverbeds and erosion exists.

• 2 Moons:1. Phobos (14 miles)2. Deimos (8 miles)

probably captured asteroids

NASA Planet Fact Site

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Mars (Continued)• Permafrost- The soil is permanently frozen. Lots of frozen

water in the soil

• Atmosphere is very thin and made mainly of carbon dioxide.– Doesn’t retain much heat from the Sun so its average

temperature is -85 F• There are strong Dust storms on Mars

NASA Planet Fact Site

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Mars (Continued)Interesting Features on Mars:• Face• Heart• Happy Face Crater• Woman

NASA Planet Fact Site

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Mars (Continued)Spacecraft: (some)

1. Mariner 4 1st to visit in 19652. Viking I and II landed in

19763. Mars Global Surveyor orbit

in 1996 4. Pathfinder in 1997 was 1st

robotic rover on mars5. Mars Odyssey orbit in 20016. Spirit and Opportunity twin

rovers in 2004 7. Mars Reconnaissance

Orbiter orbit in 20068. Phoenix Lander landed in

2008

virtual mars

http://www.jpl.nasa.gov/video/index.cfm?id=886

Drive ME!

clip

clip

NASA Planet Fact Site

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Asteroid Belt• Hundreds of thousands of rocks that

orbit the sun between Mars and Jupiter

• Thought to be matter that failed to join with a planet because of Jupiter’s strong gravitational pull.

• Made of Rock and Metal• Irregular shape (not spherical)• Vary in size• Smaller than planets• None have atmospheres• Video clip: How to prevent a collisi

on?

NASA Planet Fact Site

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Comets• Long elliptical orbits that take them far from the sun

beyond Pluto and closer to the Sun than Earth.• Made of Rock, Dust, and Ice• Smaller than planets• Irregular shaped• Develop a tail as they get close to the sun

NASA Planet Fact Site

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Meteoroid• rocky objects; smaller than asteroids and comets

• Broken off pieces of planets, moons, asteroids, or comets

Meteor• a meteoroid burning in Earth’s atmosphere

• seen as a flash of light

• “shooting star”

Meteorite• a meteor that does not completely burn up in the atmosphere

• strikes the ground

NASA Planet Fact Site

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Jupiter• Largest Planet• Very thick atmosphere of H and He• - 240 F at cloud tops• Thin ring system• Over 60 moons (4 major)• Shortest day (10 hrs) poles flatten!• Great Red Spot– 2-3x size of earth– Hurricane like storm going on for thousands of years

NASA Planet Fact Site

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Saturn

• 2nd largest planet• Will float in water (least dense planet)• - 290 F at cloud tops• Over 60 moons • Very thick atmosphere of H and He• Most extensive Ring system of any planet

• ring particles are made almost entirely of water ice, with some contamination from dust and other chemicals.

NASA Planet Fact Site

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Uranus and Neptune• Thick atmosphere made of mainly H and He• Both approx. -360 F at cloud tops• Both have thin ring systems• Uranus is tipped on its side and has 27 moons• Neptune has 13 moons

NASA Planet Fact Site