Presentation on theme: "Earth and Its Moon Chapter 4 Earth Science. The Earth - The third planet from sun - Takes 365.256 days to travel around the sun - Takes 23.9345 hours."— Presentation transcript:
Earth and Its Moon Chapter 4 Earth Science
The Earth - The third planet from sun - Takes days to travel around the sun - Takes hours for the Earth to rotate on its axis - Has atmosphere of 78% nitrogen, 21% oxygen, and 1% other constituents - Only planet to harbor life
The Earth’s Magnetosphere - Caused by the planet’s rapid spin and molten nickel-iron core - Shields us from almost all harmful radiation - Protects us from meteors
Van Allen Radiation Belts -discovered by Explorer 1 -doughnut-shaped region surrounding equator -distorted into tear-drop shape by solar wind -contains rapidly moving charged particles -auroras are seen
The Moon Earth’s only satellite Rotational period: days Orbital period: days Lunar phases: days Gravity is one-sixth that of Earth No atmosphere
Surface of Moon *craters *highlands *maria *rille
Origin of the Moon There are three theories as to how the moon was formed. 1.It was captured by Earth’s gravity. 2.It formed from the same cloud of dust and gas as the Earth. 3.It formed after an asteroid struck the Earth.
PHASES OF THE MOON Half of the moon is always in sunlight and half is always dark. The lunar view is always changing as the moon moves around the Earth. New moonFull moon Waxing crescentWaning gibbous Quarter moonLast quarter moon Waxing gibbous Waning crescent
Solar Eclipse The moon is directly between the Earth and the sun. There are two parts to the shadow – the umbra (inner shadow), the penumbra (outer shadow).
A Lunar Eclipse The earth is directly between the sun and a full moon. The moon passes through the Earth’s shadow.
Tides Tides are caused by the moon’s gravitational pull on the Earth. There are 4 tides during the course of a day – 2 high tides and 2 low tides. Spring tides are higher than usual high tides. Neap tides are lower than usual high tides.
NEIL ARMSTRONG WALKS ON MOON July 20,1969 USA
Apollo 11 Astronauts on mission Neil Armstrong (first man to walk on moon) Edwin Aldrin Jr. (pilot of lunar module “ Eagle”) Michael Collins - remained in service module
Space travel takes a new form. Now we have 7-man crews.
Satellites -are built by people -called artificial satellites -sent into outer space on the top of a rocket or in the cargo bay of the space shuttle
Types of Satellites Communication satellites – transmit information around the world Weather satellites – track weather patterns and conditions Navigation satellites – used by pilots and sailors Scientific satellites – add to our knowledge of the universe
Benefits of Space Technology Light weight tennis rackets Pacemakers Microwave oven Thinsulate clothing Various medical devices Heat absorbent packets
Pioneers in Space
January 28, Space Shuttle Challenger Exploded 73 seconds after take off killing all 7 astronauts