2. What is Earth Science?
• This learning area is designed to provide a general background for the
understanding of Earth Science and Biology
• It discusses the Earth’s structure, composition, the processes that
occur beneath and on the Earth’s surface, as well as issues, concerns,
and problems pertaining to natural hazards are also included.
• It also deals with the basic principles and processes in the study of
biology
3. 01
02 Four subsystems of Earth
03
Characteristics of Earth that are necessary to support life
Learning
Competencies:
Rock-forming minerals
(S11ES-Ia-b-3)
(S11ES-Ib-4)
(S11ES-Ib-5)
4. “We do not inherit the Earth from our ancestors;
we borrow it from our children.”
-American Indian proverb
6. What are the unique characteristics of
Earth that allow the existence of Life?
• Liquid Water
• Heat Source
• Atmosphere
• Energy
• Right Distance from Sun
• Strong Magnetic Field
• Nutrients
• It is protected by the plate tectonics from
the very hot temperature of the core
7. Liquid Water
● H20
● This matter dissolves and
transports materials in and out
of the cell. Only Earth has the
right chemical materials like
liquid water that could support
life.
● Water makes up about 71% of
the Earth’s surface, while the
other 29% consists of
continents and islands
● “Universal Solvent”
https://onewater.org.uk/wp-content/uploads/2019/03/iStock-490824286-1.jpg
8. The heat that drives the different systems necessary to support life on Earth comes
from two sources: Internal Heating of the Earth and External Heating from the
Sun.
Heat Source
Internal
Heat coming from Earth is caused by
radiogenic heat from radioactive decay of materials in the
core and mantle, and extruded via active tectonic
activities, such as volcanism and plate movement
External
Heat provide by the sun is in the form of
radiation which enters Earth. As sunlight strikes Earth,
some of the heat is trapped by a layer of gasses called
Atmosphere.
238U 235U 232Th 40K
9. Atmosphere
• The atmosphere of Earth is composed of nitrogen (about
78%), oxygen (about 21%), argon (about 0.9%), carbon dioxide (0.04%) and
other gases in trace amounts.
• Without the greenhouse effect, Earth would be frozen, more than 60º F
colder. As mentioned above, the atmosphere is capable of trapping heat
because of greenhouse gases.
Examples of greenhouse gases are water
vapor, methane, and carbon dioxide.
10. TROPOSPHERE
The troposphere is the lowest layer of Earth's atmosphere and site of all
weather on Earth. It is bonded on the top by a layer of air called the tropopause, which
separates the troposphere from the stratosphere, and on bottom by the surface of the
Earth.
STRATOSPHERE
The stratosphere is a layer of Earth's atmosphere. It is the second layer of the
atmosphere as you go upward. The troposphere, the lowest layer, is right below
the stratosphere. The next higher layer above the stratosphere is the mesosphere.
MESOSPHERE
The mesosphere is a layer of Earth's atmosphere. The mesosphere is directly
above the stratosphere and below the thermosphere. It extends from about 50 to 85
km (31 to 53 miles) above our planet. Temperature decreases with height throughout
the mesosphere.
11. THERMOSPHERE
The thermosphere is the layer in the Earth's atmosphere directly above the
mesosphere and below the exosphere. Within this layer of the atmosphere, ultraviolet
radiation causes photoionization/photodissociation of molecules, creating ions;
the thermosphere thus constitutes the larger part of the ionosphere.
EXOSPHERE
The exosphere is the uppermost region of Earth's atmosphere as it gradually
fades into the vacuum of space. Air in the exosphere is extremely thin - in many ways it
is almost the same as the airless void of outer space.
12. Energy
• Living things use light or chemical energy to run essential life processes.
With the availability of sufficient energy, organisms can perform different
metabolic reactions through the cells. The inner planets such as Earth, get
too much sunlight for life. The outer planets get too little.
• Photosynthesis
• The Earth orbits in the so-called Goldilocks zone, where the planet receives
enough energy to allow water to exist as a liquid on its surface. Too far,
and the water would freeze. Too close, and the water would rapidly
evaporate into the atmosphere.
13. Strong Magnetic Field
● It shields us from the electromagnetic
radiation coming from the Sun. The magnetic
field deflects the radiation that may destroy the
ozone layer.
● Earth's magnetic field (and the surface
magnetic field) is approximately a magnetic
dipole, with the magnetic field S pole near
the Earth's geographic north pole and the other
magnetic field N pole near the Earth's
geographic south pole.
14. Nutrients
● These are materials that build
and maintain an organism’s
body. The inner planets
including Earth and moons
have the same general
chemical components which
makes nutrients easily
available in the environment.
• There are various biogeochemical cycles and geologic processes that facilitate
the transport and replenishment of the chemicals and nutrients required by the
biotic factors. Examples include water cycle and volcanism. The presence of
volcanoes, cycle of water and atmosphere, contribute to the flow of nutrients
within earth’s systems.
15. Tectonic Plates
● The earth’s core causes the convection currents in
the mantle causing the overlaying lithosphere to
move. However, the surface is protected from heat
from the core by the lithospheric plates.
● A tectonic plate (also called lithospheric plate) is a
massive, irregularly shaped slab of solid rock,
generally composed of both continental and oceanic
lithosphere. Plate size can vary greatly, from a few
hundred to thousands of kilometers across; the
Pacific and Antarctic Plates are among the largest.
16. Summary
Factors that make a Planet
Habitable
Just Right Situation in the Solar System
Temperature
Influences how quickly atoms and
molecules move.
Life seems to be limited to a
temperature range of -150C to
1150C. In this range, liquid water
can still exist under certain
conditions.
Surface: Only the Earth’s surface
is in this temperature range. Sub-
surface: the interior of the solid
planets and moons may be in this
temperature range.
Water
Dissolves and transports
chemicals within and to from a
cell
Water is regularly available. Life
can go dormant between wet
periods, but, eventually, water
needs to be available.
Surface: Only Earth’s surface has
water, though Mars once had
surface water and still has water
ice in its polar ice caps. Saturn’s
moon, Titan, seems to be
covered with liquid methane.
Sub-surface: Mars and some
moons have deposits of
underground ice, which might
melt to produce water. Europa,
has a vast ocean beneath its
outer shell in ice.
17. Atmosphere
Traps heat, shield the surface
from harmful radiation, and
provide chemicals needed for
life, such as nitrogen and
carbon dioxide.
Earth & Venus are the right size
to hold a sufficient-sized
atmosphere. Earth’s atmosphere
is about 100 miles thick. It keeps
the surface warm & protects it
from radiation & small- to medium
sized meteorites.
Of the solid planets and Moons,
only Earth, Venus, & Titan have
significant atmospheres. Mars’
atmosphere is about 1/100th that of
Earth’s, too small for significant
insulation or shielding.
Energy
Organisms use light or
chemical energy to run their
life processes.
With a steady input of either light
or chemical energy, cells can run
the chemical reactions necessary
for life.
Surface: The inner planets get too
much sunlight for life. The outer
planets get too little. Sub-surface:
Most solid planets & moons have
energy-rich chemicals.
Nutrients
Used to build and maintain an
organism’s body.
All solid planets & moons have
the same general chemical
makeup, so nutrients are present.
Those with a water cycle or
volcanic activity can transport
and replenish the chemicals
required by living organisms.
Surface: Earth has water cycle, an
atmosphere, and volcanoes to
circulate nutrients. Venus, Titan, Io,
and Mars have nutrients and ways
to circulate them to organisms.
Subsurface: Any planet or moon
with sub-surface water or molten
rock can circulate and replenish
nutrients for organisms
