What Am I?
I’m spherical but I’m not a soccer ball
I have a core but I’m not an apple
I have a crust but I’m not a loaf of bread
I have plates, but on me food isn’t served
I have a mantle but I’m not a fireplace
I’m mostly covered by water but I’m not
an iceberg.
What am I?
EARTH
EARTH AND LIFE SCIENCE
Lesson Objective 1:
Recognize the uniqueness of Earth,
being the only planet in the solar
system with properties necessary to
support life.
Earth
Earth is the only planet in the solar system
known to harbor life. Our planet’s has molten
nickel-iron core that gives rise to an extensive
magnetic field, which, along with the
atmosphere, shields us from harmful radiation
coming from the Sun.
What do you
think are the
characteristics
of the planet
Earth that
make it
different from
all the other
planets?
Earth, Venus, and Mars may have
similarities:
(1) They all are terrestrial planets,
made of solid rocks and silicates;
(2) They all have an atmosphere;
(3) They all almost have the same time
to rotate on their axes;
(4) Earth and Mars both have water;
(5) They all have carbon dioxide; and
(6) All have landforms.
Activity 1:
Understanding Planet Earth
How is planet Earth
similar and different from
Venus and Mars?
Activity 1: (By group)
Understanding Planet Earth
Which of these criteria explain
why Earth is a living planet?
(Give 5 criteria and explain
each.)
Example:
Gravity
 Earth’s gravity is just right to keep us on
the ground.
 The gravity on Venus is lower so objects
would feel a bit lighter.
 The gravity on Mars is small so objects
will feel a lot lighter (but will not float).
SURFACE PRESSURE
 Earth’s surface pressure is just perfect, it
does not crush us down.
 The surface pressure on Venus is too high
that will crush things instantly.
 The surface pressure on Mars is too small
so living things will have difficulty in
breathing (apart form the fact that there is
a very small oxygen present in air).
COMPOSITION OF THE ATMOSPHERE
 Earth’s atmosphere has enough oxygen to
sustain life.
 The atmospheres of Venus and Mars are
mainly carbon dioxide which is toxic to
living things, thus there is no life on these
planets.
Did you know?
Venus’s atmosphere is very thick, making
it the hottest planet in the Solar system.
Mars’s atmosphere is thinner than the
Earth which makes it vulnerable to solar
radiations.
MAJOR GREENHOUSE GASES
 Earth’s greenhouse gases include carbon
dioxide and water vapor.
 The greenhouse gases of Venus and Mars
are mainly carbon dioxide.
MEAN TEMPERATURE
 Earth’s mean temperature is 15 degrees
which is enough to maintain life’s
processes.
 Venus’s mean temperature is too high
while Mars’s temperature is too low, so life
is not possible to flourish.
TEMPERATURE IF NO GRENHOUSE
GASES (GHG)
 Earth’s temperature if no greenhouse
gases will be -18 degrees Celsius.
 Venus’s and Mars’s temperature are
considerable very low/too cold for living
things to survive.
DISTANCE FROM THE SUN
 Earth’s distance from the Sun is perfect,
not too hot, not too cold.
 Venus is near to the Sun, making it a hot
planet besides having a think atmosphere.
 Mars is far from the Sun, making it a cold
planet.
DISTANCE FROM THE SUN
 Earth has a magnetic field that protects
our planet from cosmic radiation emitted
by the Sun.
 Venus and Mars have no magnetic field,
that makes them vulnerable to the harmful
effects of the cosmic radiation.
Factors That Make the Earth Habitable
Temperature
Atmosphere
Energy
Life seems to be limited
to a temperature of -15
degrees Celsius to 115
degrees Celsius.
In this range, liquid
water can still exist
under certain conditions.
The Earth is not too cold
like Neptune and not
too hot like Mercury.
Earth has the right size
to hold a sufficient
atmosphere. Earth’s
atmosphere is about 100
miles thick. It keeps the
surface warm and
protects it from radiation
and small to medium
sized meteorites.
The Earth has no thick
atmosphere like Jupiter
and has no thin
atmosphere like Mars.
With a steady input
of either light or
chemical energy, cells
can run the chemical
reactions necessary
for life.
Nutrients used to
build and maintain an
organism’s body
All solid planets and moons
have the same general
chemical make-up, so
nutrients are present.
Those with a water cycle or
volcanic activity can
transport and replenish the
chemicals required by living
organisms.
Factors That Make the Earth Habitable
Temperature
Atmosphere
Energy
Life seems to be limited
to a temperature of -15
degrees Celsius to 115
degrees Celsius.
In this range, liquid
water can still exist
under certain conditions.
The Earth is not too cold
like Neptune and not
too hot like Mercury.
Earth has the right size
to hold a sufficient
atmosphere. Earth’s
atmosphere is about 100
miles thick. It keeps the
surface warm and
protects it from radiation
and small to medium
sized meteorites.
The Earth has no thick
atmosphere like Jupiter
and has no thin
atmosphere like Mars.
With a steady input
of either light or
chemical energy, cells
can run the chemical
reactions necessary
for life.
Nutrients used to
build and maintain an
organism’s body
All solid planets and moons
have the same general
chemical make-up, so
nutrients are present.
Those with a water cycle or
volcanic activity can
transport and replenish the
chemicals required by living
organisms.
Factors That Make the Earth Habitable
Temperature
Atmosphere
Energy
Life seems to be limited
to a temperature of -15
degrees Celsius to 115
degrees Celsius.
In this range, liquid
water can still exist
under certain conditions.
The Earth is not too cold
like Neptune and not
too hot like Mercury.
Earth has the right size
to hold a sufficient
atmosphere. Earth’s
atmosphere is about 100
miles thick. It keeps the
surface warm and
protects it from radiation
and small to medium
sized meteorites.
The Earth has no thick
atmosphere like Jupiter
and has no thin
atmosphere like Mars.
With a steady input
of either light or
chemical energy, cells
can run the chemical
reactions necessary
for life.
Nutrients used to
build and maintain an
organism’s body
All solid planets and moons
have the same general
chemical make-up, so
nutrients are present.
Those with a water cycle or
volcanic activity can
transport and replenish the
chemicals required by living
organisms.
Factors That Make the Earth Habitable
Temperature
Atmosphere
Energy
Life seems to be limited
to a temperature of -15
degrees Celsius to 115
degrees Celsius.
In this range, liquid
water can still exist
under certain conditions.
The Earth is not too cold
like Neptune and not
too hot like Mercury.
Earth has the right size
to hold a sufficient
atmosphere. Earth’s
atmosphere is about 100
miles thick. It keeps the
surface warm and
protects it from radiation
and small to medium
sized meteorites.
The Earth has no thick
atmosphere like Jupiter
and has no thin
atmosphere like Mars.
With a steady input
of either light or
chemical energy, cells
can run the chemical
reactions necessary
for life.
Nutrients used to
build and maintain an
organism’s body
All solid planets and moons
have the same general
chemical make-up, so
nutrients are present.
Those with a water cycle or
volcanic activity can
transport and replenish the
chemicals required by living
organisms.
Earth is the only place in the known universe
confirmed to host life and is the only one known for
sure to have liquid water in the surface.
These are the reasons why planet Earth is a
unique one:
(1) It has liquid water;
(2) There are plate tectonics;
(3) It has atmosphere that shelters it from the
worst of the sun’s rays.
ASSIGNMENT 1
List down ten (10) activities that you can do to save
planet Earth and identify those activities as a form of
recycling, reducing, or reusing.