Earth is uniquely situated to support life. It is the third planet from the sun and located about 93 million miles away, allowing liquid water to exist on its surface. Earth's atmosphere, primarily made up of nitrogen and oxygen, maintains a temperature range that permits life. Additionally, Earth has a molten iron core that generates a magnetic field protecting the planet. Water, present as oceans, lakes, ice caps, and vapor, is critical for life and exists on Earth's surface due to its hydrologic cycle. These factors make Earth unusually habitable compared to other planets in the Milky Way galaxy.

1. EARTH
AS A
UNIQUE
PLANET

2. In the Milky
Way galaxy
alone, there
are about 1
billion
planets

3. WHY OTHER
PLANETS
UNINHABITABLE?
• They are too big
• Too small
• Too hot
• Too cold
• may not have an
atmosphere or a
magnetic field
• May not have orbit

4. • Earth is the 3rd inner planet.
• About 93 million miles away from the sun.
• about 500 seconds for sunlight to reach the
earth’s surface.
EARTHS LOCATION

5. • This distance from the sun is enough to support life.
• Producers, or organisms that manufacture their own food utilize the energy
from the sun and convert it into chemical energy that marks the beginning
of food chains and complex food webs.
• Earth’s tactical location also prevents it from planetary collisions.
EARTHS LOCATION

6. EARTH’S
ATMOSPHERE
• The atmosphere is the gaseous layer
that envelops the earth
• Most of the element that makes up the
atmosphere is nitrogen (about 78%).
• If we compare the earth to an apple,
the atmosphere is relatively the size of
its peel.

7. EARTH’S SIZE AND MASS
• As the largest of the terrestrial
planets, Earth has an estimated
mass of 5.9736 × 1024 kg. Its
volume is also the largest of
these planets at 108.321 ×
1010km3.
• The size of the earth also plays a
vital role in keeping its life
support system afloat.
• The acceleration due to gravity
helps the planet maintain its
atmosphere.
Terrestrial planets (Earth sized and smaller) are rocky worlds,
composed of rock, silicate, water and/or carbon. To determine if
some of these worlds have atmospheres, oceans or other signs of
habitability, it takes more investigation. Larger terrestrial
exoplanets (those at least twice as massive as Earth) are classified
as super-Earths.

8. EARTH’S
MAGNETIC FIELD
• Our planet is a big ball
of magnet.
• Its geographic north
serves as its magnetic
south and its geographic
south serves as its
magnetic north.
• The region around earth
that is dominated by
magnetic field is called
magnetosphere which
extends to about 65,
000 km in space.

9. PRESENCE OF WATER
• Water covers about 71% of the Earth's surface, mostly in seas
and oceans (about 96.5%). Small portions of water occur as
groundwater (1.7%), in the glaciers and the ice caps of
Antarctica and Greenland (1.7%), and in the air as vapor, clouds
(consisting of ice and liquid water suspended in air), and
precipitation (0.001%).
• Three fourths of the Earth’s surface are covered with
water.
• However, this compound may exist as ice or vapor
alone. On earth however, water exists as gas
forming clouds, as liquid in the form of oceans and
lakes and as solid in the form ice caps. This is due
to hydrologic cycle.
• Earth has the right amount of water to keep its
habitability.