4.1 Our Solar System

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4.1 Our Solar System
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4.1 Our Solar System

• What you will learn
• What makes up the solar system?
• How did the solar system form?
• How does a planets distance from the sun affect
  its period of revolution?

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4.1 Our Solar System

• What makes up the solar system?
• The sun!
• Planets moons
• Dwarf planets
• Asteroids
• Meteoroids
• Comets

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Measuring distances in the solar system

• To measure the great distances in space,
  astronomers needed a longer ruler
• Astronomical Unit (AU) the average distance
  from the earth to the sun
• The average distance is 93,000,000 miles!

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Measuring distances in space

• Astronomical Unit (AU) the average distance
  from the earth to the sun (93,000,000 miles)
• Mercury is .4 AU from the sun
• Earth is 1.0 AU from the sun
• Jupiter is 5 AU from the sun
• Pluto is 50 AU from the sun!

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Planet Orbits around the sun

• What holds the planets in orbit around the sun?
• The gravity (of the sun) inertia
• How are the orbits shaped?
• Ellipse a slightly flattened circle

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• How did the Solar System form?
• Q Where are stars born?
• A a nebula

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• The Horse Head Nebula

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Formation of the Solar System

• Our solar system began to form 4.6 billion years
  ago
• In the beginning it was just a large cloud of
  gas, ice dust in a nebula
• A super nova from a dying star caused some of the
  gas and dust to clump together
• Gravity pulled in more matter
• The clump flattened into a rotating disk

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Formation of the Solar System

• About 4.6 billion years ago our solar system
  began to form (cont)
• The cloud flattened into a rotating disk
• Most of the mass was in the center
• under the force of gravity, the temperature
  increased to about 10,000,000 degrees.
• Nuclear fusion begins H ? Helium energy
• A star is born the Sun!
• Matter (dust gas) surround the star the
  beginning of the solar system

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The beginnings of a solar system
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Formation of the Planets

• Away from the center, bits of dust and gas began
  to clump together
• Because the pull of gravity, they formed into
  spheres
• These clumps formed the inner and outer planets
• Inner planets small and rocky
• Outer planets gas giants
• Some rocks dust never formed into planets and
  remain in orbit the asteroid belt.
• Other objects are made of dust ice and remain
  at great distances from the sun the comets and
  dwarf planets

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Check your understanding Solar System

• Thumbs up I get it!
• Thumb sideways I sort of get it
• Thumb down I dont get it too much information!

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4.1 Speeding Around the Sun

• Todays Inquiry How does a planets distance
  from the sun affect its period of revolution?
• Materials
• String (yarn)
• Meter stick
• Rubber stopper
• clipboard
• stopwatch