After going through the module, learners should:
understand the formation of the universe and solar system
describe the characteristics of some planets
Cite the factors making the Earth support life
Explain that the Earth consists of four subsystems, across whose boundaries matter and energy flow
Many cosmological events took place before the Earth came to be. These events explain how the
universe was formed and how the solar system became part of the universe.
How and when did the universe begin? No one was around when the
universe began, so who can say what really happened?
A Scientific Theory is an explanation or model backed by results
obtained from many tests or experiments.
A. BIGBANG THEORY : (Widely ACCEPTED theory explain the origin of the universe)
-it states that the universe was once very small and very hot, and then it expanded over time until it
reached its peak (which may be perceived as a massive explosion for some ) around 13.7 billion
years ago (considered the age of the universe).
-it also asserts that seconds after the explosion,surroundings were at a high temperature of about 10
billion degrees Fahrenheit (5.5 billion Celsius)with aggreagtes of fundamental particles such as
neutrons,electrons, and protons.
-As the universe cooled in later phases, tehes particles either combined with each other or decayed
-It al;so state that the universe will continue to expand over the next 13 billion years untill the present
(Please refer to the image below for the chronological events occurred.)
THEORY : It states that the universe is always expanding in a constant average density
It claims that the universe has no beginning or end in time, even though it is expanding; its appearance
remains the same over time.
-proposed by Alan Guth and Andrei Linde in 1980’s
-it states that the early universe was a rapidly expanding bubble of pure vacuum energy which doesn’t have
any matter or radiation .Then, big bang occurred because of extremely hot, dense condition of matter.
Galaxies are collections of stars, gas, dust and dark matter held together by gravity. Their
appearance and composition are shaped over billions of years by interactions with groups of stars and
other galaxies. Using supercomputers, scientists can look back in time and simulate how a galaxy may
have formed in the early universe and grown into what we see today.
Galaxies are thought to begin as small clouds of stars and dust swirling through space. As other clouds
get close, gravity sends these objects careening into one another and knits them into larger spinning
packs. Subsequent collisions can sling material toward a galaxy’s outskirts, creating extensive spiral arms filled
with colonies of stars. Watch the video to see this process unfold. (See Image below)
Take note that the solar system was formed after billion years from the “explosion”.
- - states that the solar system developed out of an interstellar cloud of dust and gas, called a nebula
-According to this theory, our own solar system formed about 4.6 billion years ago, and others are
forming today in distant nebulae.
****The Nebular Theory would have started with a cloud of gas and dust, most likely left over from a previous
supernova. The nebula started to collapse and condense; this collapsing process continued for some time. The
Sun-to-be collected most of the mass in the nebula’s center, forming a Protostar (called Sun now).
NEBULAR THEORY EXPLAINS three observable facts:
1. the planets all rotate in the same direction.
2. they all orbit within 6 degrees of a common plane.
3. all the terrestrial planets, which are those within the orbit of the Asteroid Belt, are rocky, while those outside
it are gaseous.
-The theory also explains the existence of the Kuiper Belt -- a region on the fringes of the solar system with
a high concentration of comets.
The order and arrangement of the planets and other bodies in our solar system is due to the way the
solar system formed. Nearest the Sun, only rocky material could withstand the heat when the solar system was
young. For this reason, the first four planets—Mercury, Venus, Earth and Mars—are terrestrial planets. They're
small with solid, rocky surfaces.
Meanwhile, materials we are used to seeing as ice, liquid or gas settled in the outer regions of the
young solar system. Gravity pulled these materials together, and that is where we find gas giants
Jupiter and Saturn and ice giants Uranus and Neptune.
1. Terrestrial Planets : Coming from the Latin word "terra", meaning "land.
2. Jovian planets : The jovian planets, so
named because of their resemblance to
Important Questions:
1.Why is not Mercury the hottest planet?
-Mercury is nearest to the Sun but not the hottest because it has almost no atmosphere .It reaches
up to 800 degrees Fahrenheit and it gets very cold upto minus 300 degrees Fahrenheit at night .Also
it has lots of craters (no atmosphere can burn meteors) having ice inside them.
2. What is special about Venu’s and its Rotation?
-Venus is the hottest planet because it has very thick atmosphere which acts as greenhouse effect
trapping heat (its temperature cannot even melt lead) and also it rotates from east to west opposite
of its orbital revolution around the sun. (You may try roatating east to west while going west to
east,Venus is incredible! )
*****WHY IS VENUS named after the Ancient Roman goddess of love and beauty?
-Venus is bright because it is covered with clouds that reflect and scatter sunlight so it may be
seen like a moon on some parts of the Earth. At the surface , the rocks are different shades of grey,
like on Earth ,but the thick atmosphere ( ) filters the sunlight so that everything would look orange if
you were standing on Venus. It can also glow in the dark due to the process “chemiluminiscence” , In
short its al because of the composition of its atmosphere.
3.What is the great red spot?
- It is the largest (over 1000 miles across, wide enough to stretch across nearly all US states east of
Texas )with winds gusting up around 200 mph swirling wildly for about 150 years or is twice ar
large as the Earth.
-Since Jupiter is a jovian planet which means it has no solid surface , there is no solid surface that
could interact with it to weaken it. (Its made up of liquid ocean of hydrogen and atmosphere
consists of mostly hydrogen and helium)
4. Is Jupiter a ringed planet?
- it has several rings made out of dust that’s why they are very faint making them not very visible not
unlike Saturn
5.Why is Saturn partly blue in color?
- it is because of the scattering (Rayleigh scattering ) of sunlight off the molecles of the atmosphere
- It is mostly made out of helium and hydrogen with a dense core of metals like iron and nickel
surrounded by rocky material.;
6. What is the great Dark spot?
-it is a spot on Neptune and is actually a large swirling storm ,like Jupiter it desn;t have solid surface.
It was the strongest winds ever recorded on any planet, having speed up to 1500 miles per hour. It
was first discovered in 1989 by Voyager 2 and was gone when Hubble Space Telescope looked in
1994. They saw another dark spot in its northern hemisphere.
7. Why is Uranus the “sideways” planet?
-it rotates on its side because during its formation it has been smashed by other celestial bodies
making it tilted . Because of this it has weird seasons on the north pole , 21 years of nighttime in
winter ,21 years of day time in summer , and 42 years of day and night in the spring and fall. at It is 4
times larger than Earth . It is also similar with Venus’s rotation.
8. Why is Uranus Blue in color?
-It is because of methane in its atmosphere ,it rings are faint narrow and dark m the outer once are
brighter and easier to be seen.
Our solar system is the only place we know of that harbors life, but the farther we explore the more we find
potential for life in other places. Both Jupiter’s moon Europa and Saturn’s moon Enceladus have global
saltwater oceans under thick, icy shells.
A planet’s habitability, or ability to harbor life, results from a complex network of interactions between the
planet itself, the system it’s a part of, and the star it orbits. The standard definition for a habitable planet is one
that can sustain life for a significant period of time. As far as researchers know, this requires a planet to have
liquid water. To detect this water from space, it must be on the planet’s surface. The region around a star
where liquid surface water can exist on a planet’s surface is called the “habitable zone.” However, this
definition is confined to our understanding of current and past life on Earth and the environments present on
other planets. As researchers learn more and discover new environments in which life can sustain itself, the
requirements for life on other planets may be redefined.
Different types of planets may drive processes that help or hinder habitability in different ways. For example,
planets orbiting low-mass stars in the habitable zone may be tidally locked, with only one hemisphere facing
the star at all times. Some planets may be limited to only periodic or local habitable regions on the surface if,
e.g., they experience periodic global glaciations or are mostly desiccated. In order to understand the full range
of planetary environments that could support life and generate detectable biosignatures, we require more
detailed and complete models of diverse planetary conditions. In particular, understanding the processes that
can maintain or lead to the loss of habitability on a planet requires the use of multiple coupled models that can
examine these processes in detail, especially at the boundaries where these processes intersect each other.
- Energy from the sun enters the Earth while overall mass remain fixed or constant without (almost) an
exchange from space.
- Ex:Pressure Cooker
Earth’s Subsystems:
What is the most important part of our planet?
It would turn out that no single feature is significant from the
others—each one play a vital role in the function and sustainability of
Earth’s system.
A system is a collection of interdependent parts enclosed within a
defined boundary. Within the boundary of the Earth is a collection of
four interdependent parts called “spheres“: the lithosphere, hydrosphere, biosphere, and atmosphere. The
spheres are so closely connected that a change in one sphere often results in a change in one or more of the
other spheres. Such changes that take place within an ecosystem are referred to as events.
The geosphere - this is the part of the planet composed of rock and minerals; it includes the solid crust, the
molten mantle and the liquid and solid parts of the earth's core. In many places, the geosphere develops a
layer of soil in which nutrients become available to living organisms, and which thus provides an important
ecological habitat and the basis of many forms of life. The surface of the geosphere is subject to processes of
erosion, weathering and transport, as well as to tectonic forces and volcanic activity, which result in the
formation of landforms such as mountains, hills and plateaux.
The atmosphere - this is the gaseous layer surrounding the earth and held to its surface by gravity. The
atmosphere receives energy from solar radiation which warms the earth's surface and is re-emitted and
conducted to the atmosphere. The atmosphere also absorbs water from the earth's surface via the process of
evaporation; it then acts to redistribute heat and moisture across the earth's surface. In addition, the
atmosphere contains substances that are essential for life, including carbon, nitrogen, oxygen and hydrogen.
The hydrosphere - this consists of those parts of the earth system composed of water in its liquid, gaseous
(vapour) and solid (ice) phases. The hydrosphere includes: the earth's oceans and seas; its ice sheets, sea ice
and glaciers; its lakes, rivers and streams; its atmospheric moisture and ice crystals; and its areas of
permafrost. The hydrosphere includes both saltwater and freshwater systems, and it also includes the moisture
found in the soil (soil water) and within rocks (groundwater). Water is essential for the existence and
maintenance of life on earth. In some classifications, the hydrosphere is sub-divided into the fluid water
systems and the cryosphere (the ice systems).
The biosphere - this contains all living organisms and it is intimately related to the other three spheres: most
living organisms require gases from the atmosphere, water from the hydrosphere and nutrients and minerals
from the geosphere. Living organisms also require a medium for life, and are adapted to inhabit one or more of
the other three spheres. However, much of the biosphere is contained within a shallow surface layer
encompassing the lower part of the atmosphere, the surface of the geosphere and approximately the upper
100 metres of the ocean. Humans are part of the biosphere, although they are increasingly responsible for the
creation of systems that may be largely artificial (such as cities).
Energy flows
The earth is a vast, complex system powered by two sources of energy: an internal source (the decay of radioactive
elements in the geosphere, which generates geothermal heat) and an external source (the solar radiation received from
the Sun); the vast majority of the energy in the earth system comes from the Sun. Whilst some variations in these two
sources occur, their energy supplies are relatively constant and they power all of the planet's environmental systems.
Indeed, energy both drives and flows through environmental systems, and energy pathways may be highly complex and
difficult to identify. For instance, energy may take the form of latent heat which is absorbed or released when substances
change state (for example, between the liquid and gaseous phases). An example of energy flow and transformation
through an ecosystem is illustrated in 2.2.2. Energy is transferred within and between environmental systems in three
main ways:
radiation - this is the process by which energy is transmitted through space, typically in the form of
electromagnetic waves
convection - this is the physical movement of fluids (such as water or air) that contain energy in the form of
heat; convection does not occur in solids
conduction - this is the transfer of energy in the form of heat through the substance of a medium (from
molecule to molecule)
The carbon cycle - carbon is stored in the atmosphere in the form of carbon dioxide, which is absorbed by
plants and converted to carbohydrates by the process of photosynthesis. The cycle then follows food chains,
with carbohydrates being consumed by herbivores and then carnivores, being metabolised during the process of
respiration. Carbon dioxide is returned to the atmosphere as animals exhale and when organic waste and dead
organisms decay. Vegetation and animals are thus important stores of carbon, although that carbon may be
rapidly returned to the atmosphere if vegetation is burned. Soils are also important reservoirs for carbon.
Atmospheric carbon dioxide is soluble in water, in which it forms carbonic acid, which forms bicarbonate ions
and carbonate ions, which in turn form salts (such as the insoluble calcium carbonate, which accumulates in
marine sediments, marine organisms and carbonate rocks, such as limestone). Carbon is typically stored in
these forms until it is released to the atmosphere by chemical weathering.
EVALUATION: (This serves as your answer sheet, detach and submit to your subject teacher)
NAME: ________________________________________SECTION:_______________________
A. VENN DIAGRAM :From the lesson, compare steady state theory and big bang theory and
nebular theory. (Draw another one below)
state Bigbang
theory theory
B. List the conditions making the Earth Habitable.
C. Fill in each box above with the correct word from the following list:
Geosphere, Atmosphere, Biosphere, Cryosphere ,Hydrosphere