Space and the Solar System

1
Space and the Solar System

• Stars are enormous balls of superheated gases.
• The sun is a star. It is the major source of
  energy for the Earth
• The solar system consists of the sun and eight
  planetsMercury, Venus, Earth, Mars, Jupiter,
  Saturn, Uranus, and Neptune

2
Major Ideas Continued

• The Earth spins or rotates on its axis. This
  spinning causes us to have day and night.
• The Earth is tilted on its axis as it revolves
  around the sun. This explains why the seasons of
  the year change from spring and summer to fall
  and winter.
• The moon orbits the Earth. The suns light
  reflects off the moon, causing us to see the moon
  at night.

3
Stars

• Stars are enormous balls of superheated gases.
  The nearest star to Earth, after the sun, is 40
  trillion kilometers away.
• Stars are formed by clouds of gases and dust in
  space.
• These gases and dust come together and begin to
  spin. This action eventually forms a star.

4
The Sun

• The sun is one of millions of stars in the galaxy
  known as the Milky Way.
• The sun is the source of most of our energy on
  Earth and the rest of the solar system.
• The sun is the source of our heat and allows
  living things on our planet to survive.
• The suns energy id the main influence on Earths
  climate and weather.
• The sun is the largest object in our solar
  system.
• Cooler areas on the suns surface are known as
  sunspots.

5
The Planets

• Planets are objects of rock, metal, ice and gas
  that circle the sun.
• The largest planet is Jupiterten times the width
  of Earth.
• In general, the farther away a planet is from the
  sun, the cooler it is.

6
Diagrams of the Solar System

• Diagrams and models of the solar system are not
  usually made to scale.
• Scale diagrams showing how far apart the planets
  are from each other would not fit on a page in a
  book.
• The same is true of the size of the planets. The
  suns width is 10 times that of Jupiter. If
  drawings were to scale, the entire solar system
  would not fit on one page.

7
The Movement of the Earth and Moon

• Earth moves in two different ways at the same
  time it rotates and it revolves.

8
Earths Rotation

• The Earth rotates, or spins, on its axis.
• This rotation takes 24 hours, causing day and
  night on Earth.

9
Earths Revolution

• The Earth revolves,or circles, around the sun in
  just over 365 days or one year.
• The Earth tilts on its axis as it revolves.
• This tilt causes the suns rays to hit the Earth
  more directly or indirectly in the different
  hemispheres at different times of the year,
  causing our seasons.

10
Movement of the Moon

• The moon is a satellite of the Earth.
• The moon takes 29¼ days to orbit the Earth.
• The moon is about one fourth the size of Earth
• Because the moon is smaller than Earth, its
  gravitational pull is weaker.
• Something with the same mass will weigh less on
  the moon than on Earth.

11
More on the Movement of the Moon

• The pull of the moons gravity is the main cause
  of the rising and fall of ocean tides.
• The moon does not produce its own light. It
  appears bright because it reflects light from the
  sun.
• The amount of the moon that is reflected each
  night changes every 29¼ days

12
Moon Phases

• The moon changes that we see on Earth are known
  as the moons phases.
• The moon appears to change as the moon orbits
  Earth. When both the Earth and sun are on the
  same side of the moon, the moon is lit up. When
  the moon is between the Earth and the sun, the
  moon appears totally dark.
• Look on page 134 at the principal phases of the
  moon.

13
Characteristics of the Moon

• The moon is made of hard rock with craters.
• There is no water, air, soil or living things.
• There is no wind.
• There is no atmosphere and no weather like we
  have on Earth.
• Meteors hit the moon without slowing down due to
  the absence of any atmosphere.
• Temperatures on the moon range from 100 C to
  -173C.