The Solar System

							The Solar System
Inner Planets 14.3
    Components of our Solar System

•   Planets
•   Star
•   Comets
•   Asteroids
•   Satellites
•   Space Trash
•   Dark Matter
•   Particles (Dust)
•   Electromagnetic radiation
    (Photons)
                                Planets
             • There are 8 planets:
               –   Mercury
               –   Venus     Terrestrial
               –   Earth     Planets

               –   Mars
               –   Jupiter
               –   Saturn
Gas Giants     –   Uranus (YOOR uh nus)
               –   Neptune
               –   Pluto
             Inner Planets
• Mercury, Venus, Earth and Mars are
  called the inner planets

• The four inner planets are small and
  dense and have rocky surfaces

• They are often called the terrestrial planets
                      Earth
• Atmosphere extends
  100+km above the
  surface.
• Atmosphere is 78%
  Nitrogen; 21% Oxygen
• Earth is unique in our
  solar system in having
  liquid water on its
  surface
• 70% of Earth’s surface
  is covered in water.
                          Earth
• 3 main layers: crust,
  mantle, and core



• Dense core made of
  iron and nickel.
                                 Mercury
• Closest to the sun
• Similar in size to the
  Earth’s moon (smallest
  planet)


Why is it difficult for astronomers to learn
  about Mercury?
                   Mercury
• Very little atmosphere,
  causing the environment to
  be extreme
  – Day time temp: 600 degrees
    Celsius (840o F)
  – Nighttime temp: -200
    degrees Celsius (-300o F)
• Made up mainly of dense
  metal irons and nickel.
                Venus
• Similar in size to Earth
  (Earth’s twin)
• Venus’s density and internal
  structure are similar to
  Earth’s
• Takes about 7.5 Earth
  months to revolve around the
  sun
• Takes 8 months to rotate on
  its axis
• Rotates from east to west
  (retrograde rotation)
                        Venus

• Very thick atmosphere, never
  has a sunny day (clouds=
  sulfuric acid)
• Pressure of Venus’
  atmosphere is 90x greater
  than that of the Earth’s
• Atmosphere= mostly CO2
•   Surface temp: 600 degrees Celsius due
    to the greenhouse effect. HOT
    ENOUGH TO MELT LEAD!!!!!!
                      Mars
• Called the “red planet”
  due to it’s reddish
  hue.
• Atmosphere: 95%
  CO2 and only has 1%
  of the pressure of
  Earth’s atmosphere.
                          Mars
• Temperatures range
  from -140oC to 20oC
• Some water remains
  in the form of ice at its
  north pole.
• Scientists think that
  water flowed on Mars’s
  surface in the past
                         Mars
• Has seasons just like
  Earth because of it’s tilt.
• The largest volcano in our
  solar system is on Mars:
  Olympus Mons – it is
  three times the height of
  Everest and covers the
  state of Missouri
• Mars has 2 small moons:
  Phobos (27 km diameter)
  and Deimos (15 km
  diameter)
            Homework
• Read Section 3, Chapter 14
• Do the review questions on page 559