Transcript Our solar systemx

Our Solar System
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Universe
Galaxy
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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 star
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• Solar System- contains:
(1) one star (sun)
(2) planets, dwarf planets, moons
(3) Asteroids, comets, meteoroids
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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
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Galaxy
How The Sun Produces Energy:
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
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
DWARF PLANET
• Orbits the Sun
• Nearly Round
• Does not clear its own
path around the Sun
• Now have 8 planets
• 5 Dwarf Planets so far
(hundreds more to come)
• Ceres, Pluto, Haumea,
Makemake, Eris
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Inner Planets vs Outer Planets
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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
Size of planets video clip
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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 clip #2
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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 DayRotates 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.
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Venus
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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**
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Mars
• 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.
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2 Moons:
1. Phobos (14 miles)
2. Deimos (8 miles)
 probably captured asteroids
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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
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Mars (Continued)
Interesting Features on Mars:
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Face
Heart
Happy Face Crater
Woman
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Mars (Continued)
Drive ME!
Spacecraft: (some)
1. Mariner 4  1st to visit in
1965
2. Viking I and II  landed in
1976
3. Mars Global Surveyor
orbit in 1996
4. Pathfinder  in 1997 was
1st robotic rover on mars
5. Mars Odyssey orbit in
2001
6. Spirit and Opportunity
twin rovers in 2004
7. Mars Reconnaissance
Orbiter orbit in 2006
8. Phoenix Lander landed in
2008
http://www.jpl.nasa.gov/video/i
ndex.cfm?id=886
virtual mars
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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.
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Made of Rock and Metal
Irregular shape (not spherical)
Vary in size
Smaller than planets
None have atmospheres
• Video clip: How to prevent a collision?
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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
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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
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Jupiter
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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
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Saturn
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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.
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Uranus and Neptune
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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
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