WORLD GEOGRAPHY
Chapter 2
Section 1
The Earth
Our Solar System
Our Solar System
• The Sun, a star, is the center of
our solar system.
• It is about 109 times bigger than
our Earth.
• 93 million miles from Earth.
OUR OWN STAR!!
The Planets:
Neighbors in Space
• Eight planets exist in our solar
system.
• Except for Mercury and Venus,
all have satellites called moons.
Pluto is
no
longer
conside
red a
planet.
Terrestrial Planets
•
•
•
•
•
Mercury, Venus, Earth, and Mars.
All have solid rocky crusts.
Mercury and Venus are scalding hot.
Mars is a cold barren desert.
Only Earth has liquid water on the surface
and can support varieties of life.
Terrestrial Planets
Frank and Ernest
on Planets
Gas Giant Planets
• Jupiter, Saturn, Uranus, and Neptune.
• More gaseous, less dense, and larger than the
terrestrial planets.
• Each is like a miniature solar systems, with
orbiting moons and thin, encircling rings.
• Saturn’s rings can be easily seen from Earth.
Gas Giant Planets
SATURN
RINGS
CAN BE
SEEN
FROM
PLANET
EARTH
Asteroids
• Small, irregularly shaped, planet-like objects.
• Mainly found between the orbits of Mars and
Jupiter in a region called the asteroid belt.
• A few asteroids follow paths that cross the
earth’s orbit.
Asteroid Belt
COMETS
• Made of icy dust particles and frozen
gases.
• Look like bright balls with long,
feathery tails.
• Orbits are inclined at every possible
angle to the earth’s orbit.
HALLEY’S COMET
Halley’s Comet
• The comet was named in honor of Edmond
Halley, who predicted its appearance in
1758.
• The average period of Halley‘s orbit is 76
years.
• Its most famous appearance was in 1066
when it was seen at the Battle of Hastings.
• Its next passage will be in 2062.
METEOROIDS
• Chunks of rock and iron.
• Atmospheric friction usually burns them
up before they reach the earth’s surface.
• Called Meteorites when they collide with
the earth.
• A giant meteorite about 65 million years
ago may have caused the end of the
dinosaurs.
EARTH
•
•
•
•
Not a perfect sphere.
The diameter at the Equator is about 7,930
miles.
Has a circumference of about 24,900 miles.
OUR
MARBLE
BLUE
Hydrosphere
The watery areas of the
earth, including oceans,
lakes, rivers, and other
bodies of water. 70% of
the earth’s surface.
Lithosphere
Lithosphere Surface land areas of the
earth’s crust, including continents and
ocean basins. 30% of the earth’s surface
ATMOSPHERE
• A layer of gases that surrounds the
earth.
• Extends about 6000 miles above the
surface.
• 78% nitrogen, 21% oxygen, small
amounts of argon and other gases.
Biosphere
The part of the earth
where life exists.
Major Landforms
•
•
•
•
•
•
•
•
Mountains
Hills
Plateaus
Plains
Others include valleys, canyons,
and basins.
Landforms contain rivers, lakes,
and streams.
Seven Continents
•
•
•
•
•
•
•
Africa
Asia
Antarctica (no Arctic Continent)
Australia
Europe
North America
South America
Continental Shelf
The part of a continent that extends underwater. Can slope out from land as
much as 800 miles and descend to a depth of 600 feet.
Palm Island in Dubai, UAE
Mt. Everest
The highest point on
Earth at 29,035 feet
above sea level
Mariana
Trench is
the
deepest
place on
earth at
35,827 feet
below sea
level.
The Dead
Sea is the
lowest
place on
land at
1,349
feet below
sea level.
Death Valley is the lowest place in the
United States