Geography Form One Notes – The Solar System
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support plants growth. Sun rays generate heat which lead to the evaporation of water water
‘vapour forms clouds and eventually rain is formed. Climate determines the types of plant and
animal species that can survive ina particular geographical area and influcnces human
population distribution. On the other hand, human activities can lead to modification of physical
cavironments, for example soil degradation, land reclamation and forest conservation
Components of the Solar System
Name the Components ofthe Solar System
[clow are the components that make up the solar system:
1 The Sun
2 Planets
3. Comets
4 Asteroids
5. Meteors; and
6 Satellites
Importance of the Components of Solar System
Describe the importance ofthe components of solar sytem
Components of the Solar System are important because:
1. ‘They produce heat an light potential fr living organisms, for example the Sun
2. The provide habitat for humans and other living organisms, for example the Earth
3. They form craters which later hocome attractive sites for turism activites, for example
‘meteors which produce meteorites that fall on the Earth’ surface and form craters
The Sun
The Sun isa star.
Dimension of the Sun in Relation to Other Space Bodies
‘State the dimension ofthe sun in relation to other space bodies
Dimension of the Sun relative to other Space Bodies: The diameter of the sun is 14 milion
Ailometers
Characteristics of the Sun
Describe the characteristics ofthe sun
The Sun is composed of approximately 75% Hydrogen, 23% Helium and 3% other elements,
‘Therefore, the elements which make up the Earth comprise only small faction ofthe materials
Which form the Sun. These inclade Carbon, Iron, Oxygen, Silicon et. The Suni the only source
of light and beat that the planet receives. The temperature of the Sun is estimated to be
20,000,00 degrees Centigrade
Solar Energy
The Term Solar Energy
Define the term solar energy
Solar energy isthe heat and light produced from the Sun. The Sun isthe source ofall energy on
the Earth
Different Uses of Solar Energy
Suggest different uses of solar energy
Some of the diferent uses of Solar energy include
1. Drying clothes, meat, fish, fits and grains
2. Photosynthesis ingrowing plans to manufacture their own food
3. Generation of electricity
4. Formation of coal, gas and ol
5. Formation of clouds and rainfall through evaporation of water caused by the heat ofthe
Sun
6 Giving power to small radios and running small telephone systems by using silicon solar
batteries
7. Source of Vitamin D to human bodies as the bodies absorb Sunlight
8 For domestic purposes lke cooking food, heating, water
How the Use of Solar Energy Promotes Environmental Conservation
Explain how the use of solar energy promotes environmental conservation
Uilization of Solar energy in manufacturing industies reduces the production of chlorine from
industially produced chlorofluorocatbon gases which cause depletion of the azone layer. The
depletion ofthe ozone layer causes global warming, Solar energy is used as an alternative source
of energy therefore reducing the depletion of forests fr charcoal and firewood
How Solar Energy May Contribute to Emancipation of Women
Explain how solar energy may contribute o emancipation of women
REDUCED TIME BURDENS LEADING TO HIGHER-
EARNING JOBS AND INCREASED ENTREPRENEURIAL
OPPORTUNITIES
‘Women are often disproportionately responsible for houschold duis. This is prticulaly acute
in rural settings, where women spend considerable time on asks suchas collecting firewood for
‘basic cooking, heating, and lighting needs. Access to energy allows for more efficient products —
fiom those as basic asa solar lantern o those as advanced as a washing machine. These products
can reduce the time burdens of domestic responsibilities and crete time for more productive
formal engagement in the loal economy outside the home, Empirical studies that have examined
the impact of electrification on female labor rates in developing country settings reinforce this
hypothesis,
IMPROVED BASELINE CONDITIONS LEADING TO
GREATER ACCESS TO ECONOMIC OPPORTUNITIES,
‘There area multitude of studies that demonstrate that improved access to electricity improves
baseline living conditions for women, These studies show improvements to women’s health
through cleaner indor air; better nutriion and food safety due to improved refrigeration; and
improved health knowledge through better accesso mass media and more time to read netioe
and exterior lighting in rural settings often means improved security for women, enabling greater
mobility to engage in productive activities unde safe conditions. Anecdotal evidence also shows
improved education for girls a a result of acess to electricity, although most empirical studies
do not show gender-ifferentiated impacts Improving these baseline conditions facilitates the
case by which women can patcipate in the local economy: Healthy, safe, and informed
individuals are more apt o be productive.
‘The Planets
Planets in the Solar System
Locate the planets nthe solar system
Panets are bodies that revolve around the Sun. Previously, they included Mercury, Venus, Earth,
Mars, Jupiter, Satur, Uranus, Neptune and Pluto, Pluto doesnot qualify tobe a planet anymore
ast isthe smallest and doesnot revolve around the Sun. Therefore, there are currently officially
only eight plants in our Solar System. The word ‘Pane’ originates from the Greek word
“Planeta which means ‘Wandering’ asthe planets seem to move about in the Sky as wandering
stars All planets revolve around the Sun inthe same direction in orbits that are elliptical and
nearly inthe same plane. The ime taken to complete an orbit depends onthe distance from the
Sun
Relative Distance of Planets from the Earth
‘Show relative distance of planets from the earth
How far is each planet from Earth?
sually when people ask this question, what they mean is “What isthe distance between the orbit
of Earth andthe orbit ofeach planet” or “What isthe closes that each planet comes to Earth?”
(These are essentially the same question, because the plancts can’t get any closer than ther
cnbtal spacing allows.) You can compute this in a rough way by assuming that the obits are
circular and coplanar, and looking at the planetto-Sun distance for each planet. Since the
distances are so large, we usually express them in Astronomical Units (AU). (AnAUJs the
average distance from Earth to the Sun, about 150 milion kilometers or 93 million miles) The
table below lists the distance ofeach planet from the Sun in AU.
Plant Average distance fom Sun in AU
Mercury 039
Venus on
anh 10
Mars 182
dopiter 520
Satum 988
Ueans 1920
Neptune 00s
Pluto (warplane) 948
Other bodies in the Solar System
Characteristics of Comets, Asteroids, Meteors and Satellites
Describe the characteristics of comets asteroids, meteors and satellites
‘Comets are objects with leading heads and bright tails in the Sky. Sometimes they ean be seen at
night. They are composed of ice crystals and fragments of solid matte They have highly
longated orbits around the Sun. They can be seen from the Earth only when they come close to
the Sun
Asteroids are solid heavenly bodies revolving around the Sun. They are mostly found between
the orbits of Mars and Jupiter. They are in thousands and the largest has adiameter of just less
than 800 Kilometres. The bodies can only be seen with a telescope because they are very far
“Meteors are pieces of hard matter falling ftom outer Space. They can be seen when they come
close to the earth, at about 110-145 Kilometres, whereas as a result of fiction with the
atmosphere, they become hot and usually disintegrated. They fall on the Earth’s surface as large
boulders known as meteorites, ora meteor if it is one. These bodies are made of Nickel, Iron and
Silica
Satellites ate the moons ofthe Planets and they can be defined as the small bodies which rotate
on their axis and revolve around the Sun. There are only seven (7) planets which have satellites
apart from $7 satellites in the Solar System, The number of satellites depends on the size and
nature ofthe planet,
Local Incidents Linked to Meteorites
Narrate local incidents linked to meteorites
There are two known meteorites in Tanzania. One is found in Mbozi district in Mbeya region
and the other is inMalampaka in the Kwimba district in Mwanza region. These falling meteorites
hhave resulted inthe formation of craters.
The Earth
The Earth isthe only Planet among the planets in the Solar System that is known to support life
(Pluto does not qualify asa planet any moreasit isthe smallest and does not revolve around the
sun). The Earth is made up of the atmosphere (ai), hydrosphere (water bodies), the solid crust,
‘molten materials and the biosphere (living organism). Water bodies cover about three quarters of|
the Earth’s surface
‘The Shape of the Earth and its Evidence
Describe the shape ofthe arth and its evidence
‘There are many ways to prove thatthe earth is spherical, The following are some of them:
1. CIRCUMNAVIGATION OF THE EARTH: The first voyage around the world by
Ferdinand Magellan and his erew, from 1519 to 1522, proved beyond doubt thatthe earth is
spherical. No traveller going round the world by land or sea has ever encountered an abrupt edge,
lover which he would fall. Modern air routes and ocean navigation are based on the assumption
that the earth is round,
2. THE CIRCULAR HORIZON: The distant horizon viewed from the deck ofa ship at
sea, or ftom a cliff on land is always and everywhere circular in shape. This circular horizon
‘widens with increasing altitude and could only be seen on a spherical body.
3. SHIP’S VISIBILITY: When a ship appears over the distant horizon, the top of the mast
is seen frst before the hull. Inthe same way, when it leaves habour, its disappearance over the
curved surface is equally gradual Ithe earth were lat, the entire ship would be seen or obscured
all at once
4. SUNRISE AND SUNSET: The sun rises and sets at different times in different places.
‘As the earth rotates ftom west to east, places in the east see the sun earlier than those in the west.
If the earth were flat, the whole world would have sunrise and sunset atthe same time, But we
know this is not so
5. THE LUNAR ECLIPSE: The shadow cast by the earth on the moon during a lunar
eclipse is always circular. It takes the outline of an arc of a circle. Only a sphere can cast such a
circular shadow
6. PLANETARY BODIES ARE SPHERICAL: All observations from telescopes reveal
that the planetary bodies, the sun, moon, satellites and stars have circular outlines from
Whichever angle you see them. They are strictly spheres. Earth, by analogy, cannot be the only
exception.
7. DRIVING POLES ON LEVEL GROUND ON A CURVED EARTH: Engineers
when driving poles of equal length at regular intervals on the ground have found they do not give
« perfect horizontal level. The centre pole normally projects slightly above the poles at either end
because of the curvature of the earth, Surveyors and field engineers therefore have to make
certain corrections for this inevitable curvature, ie. 12.6 em to 1 km.
8. SPACE PHOTOGRAPHS: Pictures taken from high altitudes by rockets and satellites
show clearly the curved edge of the earth. This is pethaps the most convincing and the most up-
to-date proof ofthe earth’s sphericity
Earth’s Movements
‘Types of Earth’s Movements
Describe the pes of earth’s movements
The Earth sin motional the time, People cannot fee this motion because they move with i like
all other planets. There are two types of movements ofthe cath, namely:
1. Therotain of the Earth on its own axis
2 Therevolution ofthe Earth around the Sun
The Term Rotation
Describe the term rotation
Rotation refers to thespinning of a body on its axis. The earth rotates or spins om its axis in an
anti-clockwise direction, from West to East through 3600 in 24 hours. Thus for every 18 degrees
ofotation, the earth takes one hour which isthe same as four minutes for every 1 degre.
‘An axis isan imaginary line joining the N (North) and $ (South) poles through the center ofthe
Earth
Note:The rotation ofthe earth is very rapid although itis dificult to fee itsmotion. At the
equator, very point of the earth’s surface is traveling Eastwards at about 1600 Km per hour. At
latitude 40 degres, the speed is about 1280 Km pe
Evidence to Prove that the Earth Rotates
Give evidence to prove that the earth rotates
Below is evidence that proves that the Earth rotates
1. During the night, stars appear to move across the sky frm West to East
2 fone travels in a fast moving vehicle, will notice tees and other objects on both sides of
the oad are moving fast in the opposite direstion
3. Rising of the sun over the easter horizon in the moming. This shows that the point of
‘observation, that i south, is moving by rotation from West to East
4, Dayand Night. During the Earths rotations some regions face the sun while others donot
face it, Thise regions facing the sun experience day time whereas the regions which are not
facing the sun are in darkness (night), This proves that the earth i rotating,
Significances of Earth’s Rotation
Explain he significances of earth’s rotation
‘Alteration of day and night: Rotation ofthe earth causes the sides of the earth which face the
sun to experience daylight which is the day, whereas the side that is not facing the sun at that
time will be in darkness (nigh).
1. ‘The occurrence of tides inthe ocean caused by gravitational forces ofthe moon and sun
‘upon the rotation of the Earth
2. Deflection of winds and ocean curtent
3. Time difference between longitudes: The rotation is responsible for difference in time
between different places on Earth. It causes the difference of one hour in every 15 degree
interval between longitudes. The Earth rotates ftom West to East and takes 24 hours to complete
‘one rotation. The difference in time is 4 minutes for each degree of longitude
‘The Term Revolution
Define he term revolution
Revolution is defined as the movement of one body around another. The earth revolves around
the sun in an elliptical orbit, Due to the elliptical shape of the earth orbit the sun is closer to the
earth atone point ofthe year than at another.
‘The farthest (maximum distance) positon from the sun in orbit ofthe earth is called aphetion
hile the nearest position of the earth tothe Sun is known as perihelion
‘The Process of Revolution
Explain the process of revolution
‘The Earth is at aphelion each year on 4th July, when i is atthe maximum distance of 152 million
kilometer form the sun. The earth is at perihelion each year on 3rd January when it is at the
‘minimum distance of 147 million kilometers.
‘The earth’s revolution around the sun takes a year (365% days) therefore the speed of revolution
{s about 296 kilometers per second. A normal year has only 365 days. The remaining fraction of|
“day is added once in four years to make a leap year of 366 days,
‘The Result of the Earth’s Revolution Around the Sun
Describe the result ofthe earth’s revolution around the sun
“The result ofthe Earth’s Revolution around the Sun:
1. ‘The four seasons of the year; summer, autumn, winter and spring. A season is one of the
distinct period into which the year may be divided. In the northern hemisphere the summer
season months are May, June and July. Autumn months are August, September and October,
winter months are November, December and January and spring months are February, March
and April, In the southern hemisphere summer season months are November, December and
January. Autumn months are February, March and April. Winter months are May, June and July
and spring months are August, September and October. Equinox refers to the period when the
sun is overhead a the equator.
2 Change in the position of the midday sun at different times of the year. As the earth
revolves around the sun its position changes and makes it appear as iit isthe sun moving
3. Varying lengths ofthe day and night at different times of the year. The axis ofthe earth is
inclined to its elliptical plane at a certain angle of 66.5 degrees. Ifthe axis of the earth were
vertical, the sun rays would be overhead at the Equator, thus all places on the earth would always
experience 12 hours of daylight and 12 hours of night
‘The Importance of the Parallels and Meridians
‘The Parallels and Meridians
Define the parallels and meridians
Latitude refers to the angular distance North or South of the equator measured in degrees,
‘minutes and seconds, The equator is given a value of 00 It is an imaginary line which divides the
Earth into two hemispheres. The Norther hemisphere has a latitude of 90° N and the Southern
hemisphere has a latitude of 90° S
Therefore, Parallels of latitude are particular lines joining all points on the surface of the earth
and making an angle of 300° N withthe equatorial plane
How Latitudes and Longitudes are Determined
Describe how latitudes and longitudes are determined
THE IMPORTANT PARALLELS
‘The important parallels include:
1. Bquator 0”
2 Tropic of Cancer 23.5°N
3. Tropic of Capricorn 23.5°S
4. Arctic Circles 66.5°N
5. The Atlantic Circle 66.5°S
LONGITUDE
Refers tothe angular distance measured in degrees East and West of the Greenwich Meridian
Prime Meridian is the line running through the poles and the Greenwich observatory near
London. Its also known as Greenwich Meridian
Al lines of longitude are semi circles of equal length. Lines of longitude are also called
meridians. There are 360° ina circle, 180° lie east of the Greenwich Meridian and the other
180? west of Greenwich,
The Greenwich lines have been chosen by convention (meaning that any other lines could have
served the same purpose).
CALCULATION OF TIME
The earth rotates on its own axis from West to East once every twenty four hours. This means
360°of longitude are covered in a period of 4 hours or 1° in four minutes. There are places on a
siven meridian that experience midday atthe same time, Time recorded along the same meridian
is known as Local Mean Time (LMT).
Example 1
‘When the local time of Accra is 2.00pm what will be the local time of Bangui 15 degrees E
Solution
15 degrees – 0 degrees = 15 degrees
15.x4 minutes = 60
60/60 = 1 hour
‘Accra 2.00 pm + 1.00 hour time difference = 3.00 pm
Importance of a Great Circle
Explain the importance ofa great circle
‘Any citcle which divides the globe into hemispheres isa great circle. The equator is great circle
and Greenwich Meridian together with Meridian 1800 make another great cirle. The number of
sreat circles i limitless,
‘The importance of great citcles in geological applications of spherical projections is that they can
represent planes. The center ofa great circle is called its pole, Ifyou know a great ciele, you can
find its pole, and if you know the pole, you can find the great circle. Thus itis possible to
represent a plane by a single point. This fact is extensively used in advanced projection
techniques. The perimeter of equatorial plane is called primitive circle,
CHARACTERISTICS OF GREAT CIRCLES
1. All great circles divide the earth (sphere) into two hemispheres,
2. A great circle isthe largest possible crcl that can be drawn on the surface ofthe sphere
3. The radius of great circles i the same as the radius ofthe earth
USES OF GREAT CIRCLES
Great cirles are used to plot routs for ships crossing the vast oceans and aircraft ying great
distance in space. Ships and aireraft travel by following great circles in oder to save fuel and
time because the shortest route between two places is along the circle ofthe great circle which
passes through them.
Importance of Parallels and Meridians
Discuss the importance of parallels and meridians
Parallels are another name for lines of latude. You will see tha these lines do not converge, of
come together, anywhere on the globe. We eal these parallels because they are always an equal
distance apart. The frst parallel isthe equator. tis latitude 0, Latitude measures distance noth
and south from the Equator, Parallels ae lines that circle the globe
Meridian are another name fo ine of longitude. These lines are drawn on maps and globes so
that people can locate places. Meridians are lines that ran from the North Pole to the South Pole
Meridians are not parallel. They converge or come together atthe Poles. They number frm the
Prime Meriian Line 0) to 180W and from the Prime Meridian to 180E
Local time
Caleulae local time
Example 2
‘What isthe local time at Morogoro-Tanzania when tis noon at Kigal- Rwanda?
Procedure
1. Note the longitudinal position between the two point Kigali 30°E and Morogoro 45°E
2. Find the difference in degres of longitude between Kigali and Morogoro 45 degres – 30
degrees = 15 degrees
3. Multiply the difference by 4 minutes 15°x 4 minutes = 60 minutes; 60 A. 60= 1 hour
4. The time difference isto be added (+) incase of places tothe East ofa point. In case of
place othe Wes, the time difference is subtracted (). Since Morogoro isto the Eas of Kigali,
Morogoro time will be ahead ofthat of Kigalis by 1 hour, therefore time for Morogoro will
be:12.00 noon + 1 hour = 1.00 pm.
Time and Time Zone
Define time and ime zone
‘Time means duration or suitable moment for some purpose
Time zone refers toa one where standard time is acepted throughout a longitudinal zone 150 in
width
Essence of Time and Time Zone
Explain the essence of time and time zone
‘The importance of time zones is to avoid the problems in telling time if every place had its own
time set according to the loal meantime,
‘The timetable of various human activities such as television and radio programs would be
confusing if they had to show different mes
[As the time varies from place to place, different stretches of land agreed to adopt the time From
certain meridian, that time is known as standard time.
East Affican counties agreed to adopt standard time taken from meridian of 45°E When a whole
sitetch of land keeps tothe same standard time that stretch of land forms a time zone.
Variation of Standard Time in a Single Country
Explain variation of standard time in a single country
Large countries like USA, China, ete have several standard time zones with each time zone
covering about 15 degrees of longitude, There are 24 times zones in the world, The starting point
for dividing the world into 24 times zones isthe Greenwich Meridian. The standard time for
Greenwich is known as the Greenwich Meridian time (GMT)
International Date Line
Define Inernational Date Line
The Intemational Date Line is the line where date is changed or calendar day begins. Ths line
follows approximately the 1800 meridian,
Location of International Date Line
Locate International Date Line
When the time is 6.00pm on Monday 25th December, at Greenwich, the time at 1800 E
longitude will be 12 hours ahead of Greenwich Mean Time. The time at 1800 E will be 6.00am
‘on Tuesday 26th December. Therefore if one travels eastwards and crosses the date line, one will
sain a day whereas one who travels westwards across the line wll loose a day.
