chapter 2 earth as planet

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CLASS VIII CLASS VIII GEOGRAPHY GEOGRAPHY BR. HECTOR PINTO INFANT JESUS HIGH SCHOOL

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Page 1: Chapter 2 Earth As Planet

CLASS VIII CLASS VIII GEOGRAPHYGEOGRAPHY

BR. HECTOR PINTO

INFANT JESUS HIGH SCHOOL

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Natural Environments: The Natural Environments: The AtmosphereAtmosphere

GE 101 – Spring 2007GE 101 – Spring 2007Boston UniversityBoston University

MyneniLecture 03: Rotating Sphere

Jan-22-07(2 of 15)

Earth as Rotating Sphere

• Let us begin to lay the foundation for the first part of the course, which is -Energy balance of the earth system

that is, What energy comes in, how it changes form, what goes out

• The energy source for the earth is the sun. Therefore, we need to look at the earth-sun “astronomical relationship”

• We begin by looking at the earth as a Rotating, Orbiting Sphere

• From this we will be able to answer many questions about the basic climate of the earth

- Why are there seasons?

- Why is there such a temperature difference between the equator and poles?

- What effect does this temperature difference have on the circulation of the atmosphere and oceans

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Earth and MoonEarth and Moon

Presented byPresented byBr. Hector PintoBr. Hector Pinto

INFANT JESUS SCHOOL,INFANT JESUS SCHOOL,CHALLAKERECHALLAKERE

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SHAPE OF THE EARTHSHAPE OF THE EARTH Many speculations about the shape of Many speculations about the shape of

the earththe earth Babylonians thought- earth was Babylonians thought- earth was

circular in shape & surrounded by river circular in shape & surrounded by river OkeanosOkeanos

Anaximander regarded –earth as Anaximander regarded –earth as cylindrical body.cylindrical body.

Ancient Indians – earth was flat with a Ancient Indians – earth was flat with a huge mountain in the middle.huge mountain in the middle.

Pythogoras, Eratosthenes, Arya Bhatta Pythogoras, Eratosthenes, Arya Bhatta & Ptlolemy – earth spherical in shape& Ptlolemy – earth spherical in shape

Earth is geoid in shape

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Nicolaus CopernicusThe Earth moves, in two ways.• It rotates on an axis (period = 1 day).• It revolves around the sun (period = 1 year) in same direction.

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The Copernican Model

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Now – not a Now – not a perfect sphere.perfect sphere.

Flattened at the Flattened at the poles & bulging poles & bulging at the equatorat the equator

Named ‘geoid’.Named ‘geoid’.

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Our Planets At A GlanceOur Planets At A Glance EarthEarth

The Earth is the third closest planet to the sun and the fifth largest planet.

It is small and rocky and as far as we know, the only planet that has life on it.

About three quarters of the Earth's surface is covered with water and it is the only planet on which water can exist in liquid form on the surface. This is the reason

that life can be sustained on it. The Earth is about 4.5 - 4.6 billion years old.

It is orbited by one moon.

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Apollo 17 view of earth

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The Earth:The Earth:

Only planet which has a biosphereOnly planet which has a biosphere -is an oblated sphere,-is an oblated sphere, -rotates on its imaginary -rotates on its imaginary axis counterclockwise every axis counterclockwise every 24 hours or 1 day,24 hours or 1 day,-appears blue in space-appears blue in space because it is 70% water,because it is 70% water,

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Earth is unique:-Earth is unique:-

1.1. Has an atmosphereHas an atmosphere which is rich in oxygen (21%) and which is rich in oxygen (21%) and nitrogen (77%)nitrogen (77%)

* presence of oxygen has made life possible on earth.* presence of oxygen has made life possible on earth.* acts as protective blanket around the earth.* acts as protective blanket around the earth.* Ozone layer in the atmosphere absorbs the harmful * Ozone layer in the atmosphere absorbs the harmful ultraviolet radiation from the Sun & prevents it from ultraviolet radiation from the Sun & prevents it from reaching the earth.reaching the earth.* atmosphere absorbs terrestrial radiation & keeps * atmosphere absorbs terrestrial radiation & keeps earth warm during nights and winter.earth warm during nights and winter.* presence of atmosphere reduces extremes of * presence of atmosphere reduces extremes of temperature.temperature.

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We breathe:We breathe:

0

20

40

60

80

nitrogenoxygentrace

nitrogen 78

oxygen 21

trace 1

percen

78% nitrogen78% nitrogen21% oxygen21% oxygen 1% argon, neon, 1% argon, neon,

carbon dioxide, carbon dioxide, neon, & kryptonneon, & krypton

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2. Has abundance of water – 70% of earth’s surface 2. Has abundance of water – 70% of earth’s surface covered by ocean and seas.covered by ocean and seas.* called watery planet* called watery planet* layer of water is called hydrosphere.* layer of water is called hydrosphere.* water is present in solid and liquid.* water is present in solid and liquid.* water appears in gaseous state in the atmosphere also.* water appears in gaseous state in the atmosphere also.* water is essential for supporting plants, animals and * water is essential for supporting plants, animals and other life forms on earth.other life forms on earth.* water in oceans helps to moderate the temperature * water in oceans helps to moderate the temperature conditions on earth which makes the circulation of water conditions on earth which makes the circulation of water possible. possible.

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Layer of rocks which form the surface of Layer of rocks which form the surface of the earth is called LITHOSPHERE.the earth is called LITHOSPHERE.

Lithosphere provides valuable soil layer Lithosphere provides valuable soil layer which sustains all plant life which supports which sustains all plant life which supports the greenhouse effectthe greenhouse effect

Plants in turn support directly or indirectly Plants in turn support directly or indirectly all forms of life on earthall forms of life on earth

Also provides all mineral resources Also provides all mineral resources needed by usneeded by us

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The combination of favourable physical The combination of favourable physical environment has made Earth a environment has made Earth a HABITABLE PLANET.HABITABLE PLANET.

Variety & abundance of plants, animals Variety & abundance of plants, animals and other forms of life make Earth unique and other forms of life make Earth unique planet.planet.

No life in other planetsNo life in other planets

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Various forms of life Various forms of life on earth constitute on earth constitute the BIOSPHEREthe BIOSPHERE

Earth has provided an Earth has provided an environment for the environment for the evolution of human evolution of human beings and the beings and the progress of human progress of human civilizationcivilization

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How did life begin?How did life begin?

It is thought that life began when lightning It is thought that life began when lightning hit the sea. hit the sea.

Lightening sent energy into the water.Lightening sent energy into the water.Chemicals in the sea were mixed together Chemicals in the sea were mixed together

by energy.by energy.New substances called amino acids were New substances called amino acids were

made from which life was able to grow.made from which life was able to grow.

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AMAZING!AMAZING!

The first living things on earth were so The first living things on earth were so small you could fit thousands of them on small you could fit thousands of them on the head of a pin. the head of a pin.

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What were the first living things?What were the first living things?

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BACTERIA.BACTERIA.

They lived in the sea. Some bacteria They lived in the sea. Some bacteria changed into alage, which were simple changed into alage, which were simple plants. Alage lived in the sea in masses, plants. Alage lived in the sea in masses, like huge blankets.like huge blankets.

They made oxygen which helped to turn They made oxygen which helped to turn the sky and sea blue.the sky and sea blue.

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ANTIPODAL BALANCE BETWEEN ANTIPODAL BALANCE BETWEEN LAND AND WATERLAND AND WATER

There is an anipodal balance of land and water directly opposite sides of the Earth.

1. Land on one side of the globe is balanced by water on the other side of the earth. For instance, the North Polar Arctic Ocean is opposite the Antarctic continent.

2. Northern Hemisphere is girdled by the land masses of the North America and Eurasia and Southern Hemisphere are the continents of South America, Africa and Australia

3. The landmass of Antarctica has three prominent protruding areas – one towards South America, another towards South Africa and a third towards Australia

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SHAPE OF THE EARTHSHAPE OF THE EARTH In old days, earth was considered to be a In old days, earth was considered to be a

flat disc with steep edges.flat disc with steep edges. All heavenly bodies revolved around the All heavenly bodies revolved around the

Earth.Earth. Aryabhatta , famous Indian astronomer, Aryabhatta , famous Indian astronomer,

believed Earth was spherical in shape believed Earth was spherical in shape and rotated on its axis.and rotated on its axis.

In Europe, Greek philosopher Pythagoras In Europe, Greek philosopher Pythagoras and Aristotle were first to state that Earth and Aristotle were first to state that Earth was spherical in shape. Considerable was spherical in shape. Considerable opposition to this view.opposition to this view.

Now we have convincing evidence from Now we have convincing evidence from man’s landing on the Moon that the man’s landing on the Moon that the Earth is spherical in shape, the evolution Earth is spherical in shape, the evolution of this idea may be considered briefly. of this idea may be considered briefly.

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Proofs for shapeProofs for shape LUNAR ECLIPSE:The earth LUNAR ECLIPSE:The earth

casts a shadow on the moon casts a shadow on the moon during a lunar eclipse. This during a lunar eclipse. This shadow is always semi-shadow is always semi-circular in shape circular in shape

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SUNRISE AND SUNSET: The fact that SUNRISE AND SUNSET: The fact that the time of sunrise varies from place to the time of sunrise varies from place to place on the Earth proves that the Earth is place on the Earth proves that the Earth is not a flat disc.not a flat disc.

If the earth was flat, all places on the earth If the earth was flat, all places on the earth would have sunrise and sunset at the would have sunrise and sunset at the same time.same time.

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CircumnavigationCircumnavigation

If we travel around the earth without changing If we travel around the earth without changing the direction, we arrive at the place we started the direction, we arrive at the place we started from.from.

As the earth is spherical in shape, it is possible As the earth is spherical in shape, it is possible to circumnavigate the earth.to circumnavigate the earth.

Magellan’s crew was first to go round the earth Magellan’s crew was first to go round the earth in a ship and complete the voyage without in a ship and complete the voyage without encountering a sharp edge.encountering a sharp edge.

Now aircrafts make many trips round the world Now aircrafts make many trips round the world on scheduled flights.on scheduled flights.

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SIGHTING A SHIP:

When a ship approaches the When a ship approaches the shore, a person standing on shore, a person standing on the shore can see the smoke the shore can see the smoke at first and then the chimney at first and then the chimney and then the ship as a whole.and then the ship as a whole.

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ARTIFICIAL SATELLITESARTIFICIAL SATELLITES

The photographs of the The photographs of the earth & other planets sent earth & other planets sent by the artificial satellites by the artificial satellites prove that the earth is prove that the earth is round.round.

Aerial photographs from Aerial photographs from space show earth space show earth spherical. Astronauts spherical. Astronauts have taken pictures of have taken pictures of earth from moon showing earth from moon showing its spherical shape.its spherical shape.

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SHAPE OF THE EARTHSHAPE OF THE EARTH

Now – not a perfect sphere.Now – not a perfect sphere. Flattened at the poles & Flattened at the poles &

bulging at the equatorbulging at the equator Named ‘geoid’.Named ‘geoid’. At equator diameter measures At equator diameter measures

12,756 km12,756 km Poles the diameter is 12,714 Poles the diameter is 12,714

k.m. giving a difference of k.m. giving a difference of 42km.42km.

Earth is geoid in shape

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)

• We begin by looking at the earth as a Rotating, Orbiting Sphere

12756 km

12714 km

N

S

- Approximately spherical- Actually an “oblate ellipsoid”- Slightly compressed from north to south- Slightly bulging from east to west- But, we treat it as a sphere

Shape of the Earth

The Blue Marble

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SIZE OF THE EARTHSIZE OF THE EARTH

Average diameter is about 12,735 km.Average diameter is about 12,735 km.Four planets – Mercury, Venus, Mars and Four planets – Mercury, Venus, Mars and

Pluto (?) are smaller than the Earth.Pluto (?) are smaller than the Earth.Others are largerOthers are largerEarly attempt made to estimate the size in Early attempt made to estimate the size in

33rdrd century BC by Greek philosopher century BC by Greek philosopher called Eratosthanes. called Eratosthanes.

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Comparison between moon and Comparison between moon and earthearth

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Earth’s MoonEarth’s Moon

Only natural satellite- avge distance from Earth is Only natural satellite- avge distance from Earth is 3,84,000km.3,84,000km.

Its diameter is 3470 kmIts diameter is 3470 km Moons duration of one rotation is apprx 29 days 5 Moons duration of one rotation is apprx 29 days 5

hours, usually calculated as 29 dayshours, usually calculated as 29 days Revolution around the earth takes approx 27 days Revolution around the earth takes approx 27 days

and 3 hours- counted as 27 daysand 3 hours- counted as 27 days The moon’s surface is covered in dust and rocky The moon’s surface is covered in dust and rocky

debris from meteor impacts. It has no water or debris from meteor impacts. It has no water or atmosphere. The dark areas of the moon are atmosphere. The dark areas of the moon are called called maria maria (Maria is a Latin word meaning (Maria is a Latin word meaning “seas”). Maria are large craters which have been “seas”). Maria are large craters which have been filled by solidified lava.filled by solidified lava.

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Full moonFull moon The moon reflects light The moon reflects light

from the sun onto the from the sun onto the earth’s surface. earth’s surface. Sometimes the moon may Sometimes the moon may appear reddish-brown in appear reddish-brown in color as the sunlight is color as the sunlight is deflected through dust in deflected through dust in the earth’s atmosphere.the earth’s atmosphere.

The moon’s gravitational The moon’s gravitational effects on the earth are effects on the earth are most apparent in the most apparent in the “coming” and “going” of “coming” and “going” of the tidesthe tides

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MoonMoon Appears so large Appears so large

because it is so close to because it is so close to earth but diameter is earth but diameter is quarter of the Earth’s quarter of the Earth’s diameterdiameter

Experiences extreme of Experiences extreme of temperature- no temperature- no atmosphere- its day atmosphere- its day temperature is 134degree temperature is 134degree C and night temperature C and night temperature is about -170 C duing two is about -170 C duing two week long lunar nightweek long lunar night

Since no atmosphere, no Since no atmosphere, no weather conditionsweather conditions

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Surface of the MoonSurface of the Moon

Many craters have been Many craters have been detected on surfacedetected on surface

Some of the mountain Some of the mountain ranges like Leibnitz near ranges like Leibnitz near the Moon’s south pole the Moon’s south pole has a height of 10670 m-has a height of 10670 m-higher than Mount higher than Mount EverestEverest

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Who was the first person to land on the Moon?

NEIL ARMSTRONG Which Year? 21st July, 1969

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Footprint of an astronaut on the Footprint of an astronaut on the surface of the moonsurface of the moon

Erosion takes place at Erosion takes place at very slow rate very slow rate because of lack of rain because of lack of rain and wind.and wind.

Footprints will not Footprints will not disappear for many; disappear for many; yeas.yeas.

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Apollo 16's Lunar Roving Vehicle parked at Apollo 16's Lunar Roving Vehicle parked at the side of the bowl-shaped, 40 metres the side of the bowl-shaped, 40 metres

wide, Plum craterwide, Plum crater

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Mars in comparison with EarthRelatively small planet, half the size of the earth

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I bet you know the answers!I bet you know the answers!

What causes day & night?What causes day & night? Which one is bigger the earth or the moon?Which one is bigger the earth or the moon? Where does the moon get its light from?Where does the moon get its light from? What percent of the earth is always lit by the sun?What percent of the earth is always lit by the sun? How many stars are in our solar system?How many stars are in our solar system? How many days does it take for the Earth to revolve How many days does it take for the Earth to revolve

around the sun?around the sun? How many low and high tides on Earth every 24 How many low and high tides on Earth every 24

hours?hours?

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Outline• the Moon is a bit of an oddball• formation of the moon, a rough start• Earth’s climate• precession - the Earth as a spinning top• the Moon and stability of Earth’s climate

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Where does the Where does the moon get its light?moon get its light?

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It actually gets its It actually gets its light from the sun.light from the sun.

How Does it do that?How Does it do that?

Just like a mirror.Just like a mirror.

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PHASES OF THE MOONPHASES OF THE MOON

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Phases of the Moon Phases of the Moon

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GLOSSARYGLOSSARY

Orbit - The path of the Moon around the Orbit - The path of the Moon around the Earth.Earth.

Rotate - The Earth spins around, like a Rotate - The Earth spins around, like a top, about its axis once each day.top, about its axis once each day.Waning - Shrinking.Waning - Shrinking.

Waxing - GrowingWaxing - GrowingGibbous - Swollen on one sideGibbous - Swollen on one side   

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What causes the What causes the phases of the Moon?phases of the Moon?

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The phases of the moon are The phases of the moon are caused by the relative positions caused by the relative positions of the earth, sun, and moon. The of the earth, sun, and moon. The moon goes around the earth, on moon goes around the earth, on average, in 27 days 7 hours 43 average, in 27 days 7 hours 43

minutes.minutes.

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MOON PHASESMOON PHASES

As the moon circles the Earth, the shape As the moon circles the Earth, the shape of the moon appears to change; this is of the moon appears to change; this is because different amounts of the because different amounts of the illuminated part of the moon are facing us. illuminated part of the moon are facing us. The shape varies from a full moon (when The shape varies from a full moon (when the Earth is between the sun and the the Earth is between the sun and the moon) to a new moon (when the moon is moon) to a new moon (when the moon is between the sun and the Earth). between the sun and the Earth).

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Oooh!Oooh!

Aaah!Aaah!

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New MoonNew Moon

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Waxing CrescentWaxing Crescent

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First QuarterFirst Quarter

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Waxing GibbousWaxing Gibbous

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Full MoonFull Moon

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Waning GibbousWaning Gibbous

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Last QuarterLast Quarter

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Waning crescentWaning crescent

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Full Moon Full Moon

A full moon appears A full moon appears as an entire circle in as an entire circle in the sky the sky

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Quarter Moon/Half Moon Quarter Moon/Half Moon

A half moon looks like A half moon looks like half a circle. It is half a circle. It is sometimes called a sometimes called a quarter moon quarter moon

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Crescent Moon Crescent Moon

A crescent moon is A crescent moon is part way between a part way between a half moon and a new half moon and a new moon, or between a moon, or between a new moon and a half new moon and a half moon. moon.

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New MoonNew Moon

The new moon is the The new moon is the phase of the moon phase of the moon when the moon is not when the moon is not visible from Earth, visible from Earth, because the side of because the side of the moon that is the moon that is facing us is not being facing us is not being lit by the sun. lit by the sun.

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Phases Phases of the of the MoonMoon

Remember the ‘right hand rule’ for orbits.

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Sun, Earth, and MoonSun, Earth, and Moon

Lunar PhasesLunar PhasesEclipsesEclipsesTides Tides Celestial MotionCelestial Motion

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Phases of the MoonPhases of the Moon

The appearance or shape of the Moon gradually changes through the course of a month. This cycle - the cycle of lunar phases, may be explained if we state the following:

1. The Moon is spherical in shape. 2. The Moon is not self-luminous, but rather

reflects the light of the distant Sun. 3. The Moon circles the Earth once per month.

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As the Moon ChangesAs the Moon Changes

NSF North Mississippi GK-8

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The Moon is not a light source, it does not The Moon is not a light source, it does not make its own light. The moon reflects light make its own light. The moon reflects light from the sun. We can see the from the sun. We can see the Moon Moon because because light from the Sun bounces light from the Sun bounces off off it back to the it back to the EarthEarth. If the . If the Sun Sun wasn't wasn't there, we wouldn't be able to see it. there, we wouldn't be able to see it.

The Sun always lights up (illuminates) half The Sun always lights up (illuminates) half of the Moon at one time. of the Moon at one time.

The Moon appears to change shape but The Moon appears to change shape but what we are actually seeing is the Moon lit what we are actually seeing is the Moon lit up by the light from the Sun in different up by the light from the Sun in different ways on different daysways on different days

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The image on the The image on the right shows you what right shows you what you would see if you you would see if you looked at the moon looked at the moon tonight .tonight .If it is black then it's a If it is black then it's a new moon.  new moon. 

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Why does the moon have Why does the moon have phases?phases?

The revolution of the Moon The revolution of the Moon around the Earth causes the around the Earth causes the Moon to appear to have Moon to appear to have phases.phases.

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8 Phases of the Moon8 Phases of the Moon

New MoonNew Moon

Waxing CrescentWaxing Crescent

First Quarter or First Quarter or Half MoonHalf Moon

Waxing GibbousWaxing Gibbous

Full MoonFull Moon

Waning GibbousWaning Gibbous

Last Quarter or Last Quarter or Half MoonHalf Moon

Waning CrescentWaning CrescentNSF North Mississippi GK-8

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New MoonNew Moon

The moon is not The moon is not visible from Earth. visible from Earth. The moon is between The moon is between the Sun and the the Sun and the Earth.Earth.

The dark side is The dark side is facing us.facing us.

This phase lasts one This phase lasts one night.night.

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Waxing CrescentWaxing Crescent Waxing means that the Waxing means that the

bright side is increasing. bright side is increasing. The right side is the The right side is the bright side.bright side.

Less than one half of the Less than one half of the moon is illuminated.moon is illuminated.

This phase includes any This phase includes any visible moon from a small visible moon from a small sliver to almost half. sliver to almost half.

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First Quarter or Half MoonFirst Quarter or Half Moon

The entire right side of The entire right side of the moon is illuminated.the moon is illuminated.

The moon looks like a The moon looks like a half circle.half circle.

The illuminated side is The illuminated side is increasing. increasing.

This phase only lasts This phase only lasts one night.one night.

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Waxing GibbousWaxing Gibbous

Gibbous means that Gibbous means that more than one half is more than one half is visible, but it is not visible, but it is not quite full.quite full.

This phase includes This phase includes the night after the first the night after the first quarter to the night quarter to the night before the full moon. before the full moon.

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Full MoonFull Moon

The moon is full and The moon is full and bright. It looks like a bright. It looks like a large circle.large circle.

The illuminated side The illuminated side is facing us.is facing us.

Only happens one Only happens one night per lunation.night per lunation.

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Waning GibbousWaning Gibbous

The moon appears The moon appears more than half but not more than half but not quite full.quite full.

Waning means that the Waning means that the illuminated side is illuminated side is decreasing. decreasing.

The left side is the The left side is the bright side.bright side.

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Last Quarter or Half MoonLast Quarter or Half Moon

Left Half of the moon Left Half of the moon is illuminated. is illuminated.

The illuminated side The illuminated side is decreasing.is decreasing.

This phase also only This phase also only lasts for one night.lasts for one night.

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Waning CrescentWaning Crescent

Less than one half of Less than one half of the moon is the moon is illuminated. illuminated.

The moon will The moon will continue to become continue to become smaller and smaller.smaller and smaller.

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NSF North Mississippi GK-8

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: Phases and Shadows Experiment

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Questions???Questions???

(ending) New Moon(ending) New Moon   Full MoonFull Moon   Waxing Gibbous MoonWaxing Gibbous Moon   Waning (decreasing) Gibbous MoonWaning (decreasing) Gibbous Moon   Waxing (increasing) Crescent MoonWaxing (increasing) Crescent Moon   Half MoonHalf Moon   Waning Crescent MoonWaning Crescent Moon   Half MoonHalf Moon   (for beginning) New Moon(for beginning) New Moon

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11   (for beginning) New Moon (for beginning) New Moon

22   Waxing (increasing) Crescent Moon Waxing (increasing) Crescent Moon

33   Half Moon Half Moon

44   Waxing Gibbous Moon Waxing Gibbous Moon

55   Full Moon Full Moon

66   Waning (decreasing) Gibbous Moon Waning (decreasing) Gibbous Moon 77   Half Moon Half Moon

88   Waning Crescent Moon Waning Crescent Moon

9 (ending) New Moon9 (ending) New Moon

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Which of the following is a true Which of the following is a true statement.statement.

                        a. A waning moon is increasing in size. a. A waning moon is increasing in size.             b. A waxing moon is increasing in size.             b. A waxing moon is increasing in size.             c. A waxing moon is decreasing in size.             c. A waxing moon is decreasing in size.             d. Waxing and waning mean the same.             d. Waxing and waning mean the same.             e. All of the answers are true.             e. All of the answers are true.             f. All of the answers are false.             f. All of the answers are false.

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When the moon is seen from When the moon is seen from the Earth as a whole circle, it is the Earth as a whole circle, it is

called a-called a-

AA Crescent moonCrescent moonBB Full moonFull moonCC Half moonHalf moonDD New moonNew moon

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When the moon is seen from the Earth When the moon is seen from the Earth as a whole circle, it is called aas a whole circle, it is called a

FULL MOON.FULL MOON.

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Which of these is the next Which of these is the next phase of the moon?phase of the moon?

New Moon --- Waxing Crescent --- ?New Moon --- Waxing Crescent --- ?

F Full MoonF Full MoonG Waning CrescentG Waning CrescentH First QuarterH First QuarterJ Waxing GibbousJ Waxing Gibbous

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The next major phase of the The next major phase of the moon would be…moon would be…

First quarter.First quarter.

Just think about it…theJust think about it…the New moonNew moon (can only get (can only get

bigger. Or = Waxing)..bigger. Or = Waxing).. Then comes Then comes Waxing crescentWaxing crescent

…next is…next is First quarterFirst quarter…then …then Waxing GibbousWaxing Gibbous and then a and then a Full MoonFull Moon..

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The waning phase of the Moon occurs The waning phase of the Moon occurs between _______________.between _______________.

a.a. New Moon and Full MoonNew Moon and Full Moon

b.b. Full Moon and New MoonFull Moon and New Moon

c.c. First Quarter and Third QuarterFirst Quarter and Third Quarter

d.d. Third Quarter and First QuarterThird Quarter and First Quarter

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b. Full Moon and New Moonb. Full Moon and New Moon

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Did you know?Did you know?

Why is only one side of the moon visible Why is only one side of the moon visible from the earth?from the earth?

We always see the same side of the moon. We always see the same side of the moon. The Moon always keeps the same side The Moon always keeps the same side pointing towards us so we can never see pointing towards us so we can never see the 'back' of the Moon from the Earth. the 'back' of the Moon from the Earth.

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The moon revolves or The moon revolves or orbits the Earth once orbits the Earth once every 29 days.every 29 days.

We all ways see the We all ways see the same side of the moon same side of the moon because the moon because the moon rotates and revolves at rotates and revolves at about the same speed.about the same speed.

The opposite side of The opposite side of the moon is hidden the moon is hidden from our viewfrom our view

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The Phases of the MoonThe Phases of the Moon

Students arrange tactile moon phase cards in a Students arrange tactile moon phase cards in a sequence that makes sense,sequence that makes sense,

identify the names of the moon phases, identify the names of the moon phases, and learn where the moon is at each phase. and learn where the moon is at each phase.

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Fun Facts for LunaticsFun Facts for Lunatics•Lunar Libration: The spin of the Moon proceeds at a uniform rate while the orbit is at a slightly nonuniform rate. The spin can get a little bit ahead or behind the orbit. Hence the face of the Moon presented to the Earth rocks back and forth by some 6° each month, a phenomenon known as longitudinal libration.

•The Moon's orbital plane: The plane of the Moon's orbit is tilted by 5° with respect to that of the Earth's orbit. Hence the rotation axis of the Earth is tilted with respect to the Moon's orbital plane by an amount within 5° of 23.5°, depending on whether the two tilts are in or out of phase. The length of time between moonrise and moonset for, say, a full Moon varies with the season as well. (Also, note the phasing between the two tilts varies continually with time, going full circle every 18.6 years.)

•The variable speed of the Moon: Like the Earth, the Moon moves in a slightly elliptical orbit as well. Hence, while the average time elapsed from, say, New Moon to First Quarter is 7.4 days, the actual time can be as short as 6.7 days near perigee (closest approach to Earth) or as long as 8.1 days near apogee.

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Moon at Perigee and ApogeeMoon at Perigee and Apogee

Distance: 359,861 km

Distance: 405,948 km

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When this photo was taken by the crew of Apollo 8, was the Moon waxing or waning as seen from Earth?

North Pole

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EclipsesEclipses Celestial bodies are Celestial bodies are

always “eclipsing” or always “eclipsing” or moving in front of each moving in front of each other. other.

Eclipses occur at Eclipses occur at predictable intervals.predictable intervals.

Other names include: Other names include: Transits and Occultations.Transits and Occultations.

Solar Eclipses can be Solar Eclipses can be total, partial, or annulartotal, partial, or annular

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Moon's shadow on Earth taken by French cosmonaut Jean-Pierre Haigneré aboard the Mir

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Lunar eclipseLunar eclipse

How Does the moon How Does the moon change its phase?change its phase?

Experiment Experiment

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"Here lie the bodies of Ho and Hi,Whose fate, though sad, is risible;Being slain because they could not spyTh' eclipse which was invisible."

Author unknown: Said to refer to the Chinese eclipse of 2136 BC or 2159 BC.

"On the day of the new moon, in the month of Hiyar, the Sun was put to shame, and went down in the daytime, with Mars in attendance."

One of the earliest written records of an eclipse of the Sun, on 3 May 1375 BC, found in the city of Ugarit in Mesopotamia.(Reprinted, from Chasing the Shadow, copyright 1994 by Joel K Harris and Richard L Talcott, by permission of Kalmbach Publishing Co.

"If the Sun at its rising is like a crescent and wears a crown like the Moon: the king wll capture his enemy's land; evil will leave the land, and (the land) will experience good . . . "

Refers to a solar eclipse of 27 May 669 BC.Rasil the older, Babylonian scribe to the king.Quoted in Historical Eclipses and Earth's Rotation, by F Richard Stephenson, Cambridge University Press, 1997, page 125.

"Nothing can be surprising any more or impossible or miraculous, now that Zeus, father of the Olympians has made night out of noonday, hiding the bright sunlight, and . . . fear has come upon mankind. After this, men can believe anything, expect anything. Don't any of you be surprised in future if land beasts change places with dolphins and go to live in their salty pastures, and get to like the sounding waves of the sea more than the land, while the dolphins prefer the mountains."

May refer to a total solar eclipse of 6 April 648 BC. Archilochus, Greek poet (c680-640 BC) Quoted in Historical Eclipses and Earth's Rotation, by F Richard Stephenson, Cambridge University Press, 1997, page 338. Partly quoted in Encyclopaedia Britannica CD 98.

ECLIPSE QUOTES

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1882 Transit(USNO)

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Application to Exo Planet Application to Exo Planet StudiesStudies

HD 209458 (mv = +7.7) in Pegasus

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When the moon is new or full, the gravitational forces of the sun and moon are pulling at the same side of the earth. (See the diagram below.) This occurrence creates the extra large "spring" tides.

When the moon is at first and third quarter, the gravitational forces of the sun and moon are pulling at 90 degrees from each other. (see the diagram below.) This occurrence yeilds little net tides called neap tides.

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More Fun Tidal Tales….More Fun Tidal Tales….Every few years people that measure such things (chronologists?) need to add a leap second to the year. The Earth's rotation is decelerating at a rate of about 0.002 seconds per day per century.

The Earth will eventually stop slowing down – when it’s rotation is equal to the moon’s orbital period !!!

The Proxigean Tide occurs when the Moon is at its closest point in its orbit to the Earth and in its New or Full Moon phase. At this time, its tidal effect on the Earth is maximum. The times when this will happen often coincide with major coastal flooding events. Between 1997 and 2020 there will be 102 times when this will happen.

The moon shows the same face to the Earth because it was deformed by Earth’s gravity when it was still molten. Earth uses this “memory” to grab the moon and slow its spin rate down.

WHY ?

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Which one is the smallest?Which one is the smallest?Which one is the largest?Which one is the largest?

Can you put these in Can you put these in size order?size order?

Place the following in Place the following in order from largest to order from largest to smallest.smallest.

MoonMoonSunSunEarthEarth

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Answer: Sun, Earth, then Answer: Sun, Earth, then moonmoon

The sun is the largestThe sun is the largest Next in size is the Earth.Next in size is the Earth. The moon is smaller than the The moon is smaller than the

Earth.Earth.

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Which of these Which of these is the biggest?is the biggest?

FF The moonThe moon GG The EarthThe Earth HH The sunThe sun JJ JupiterJupiter

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Answer: H The sun Answer: H The sun is the largest!is the largest!

Our sun is the only star in our Our sun is the only star in our solar system. The sun is also the solar system. The sun is also the largest heavenly body in our solar largest heavenly body in our solar

system.system.

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The Axis of the earthThe Axis of the earth

The axis of the earth is imaginary line that The axis of the earth is imaginary line that passes through the north pole and the passes through the north pole and the south pole.south pole.

The earth is inclined at an angle of 66.5 The earth is inclined at an angle of 66.5 degree to the plane of its orbit.degree to the plane of its orbit.

This is known as the angle of inclination. This is known as the angle of inclination. The northern point of the axis always face The northern point of the axis always face

the pole star.the pole star.

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INFANT JESUS

SCHOOL<---

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Earth is not stationary. * Always in constant motion.The Earth moves, in two ways.• It rotates on an axis (period = 1 day).• It revolves around the sun (period = 1 year).

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•Rotation:- earth rotates on its own axis from west to east. This movement is known as ROTATION

The earth takes 23 hours & 56 minutes & 4.09 seconds to complete one rotation. The average time required for the earth’s rotation from one sunrise to another sunrise is 24 hours. This period is known as a solar day.

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Each team will need a scorekeeper --->

Life on earth is affected in many was as the earth spins on its own axis.

Day & night are the result of the earth’s rotation.

As the earth rotates on it’s axis only one half of the earth faces to sun at a given time.

It is a day on the side of the earth which is turned towards the sun and receives light, & night for the other half of the earth which is away from the sun and is covered in darkness.

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Different stages of the day like morning, Different stages of the day like morning, noon and evening are experienced noon and evening are experienced because of the earth’s rotation.because of the earth’s rotation.

Sun, moon, stars & planets seem to rise in Sun, moon, stars & planets seem to rise in the east & set in the west.the east & set in the west.

This is due to rotation of the earth.This is due to rotation of the earth.With the rising sun as the point of With the rising sun as the point of

reference, it is possible to have a sense of reference, it is possible to have a sense of other directions as well.other directions as well.

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Midnight

Noon

Sunrise

Sunset

The Earth rotates towards the east

(CCW)

The Earth’s Rotation: The Earth’s Rotation: Daily Motion Daily Motion

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RevolutionRevolution

The earth revolves around the sun as well. The earth revolves around the sun as well. This movement around the sun is known This movement around the sun is known as the earth’s revolution.as the earth’s revolution.

It takes a year for the earth to go around It takes a year for the earth to go around the sun once.the sun once.

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Fall Stars

Spring Stars

Summer Stars

Winter Stars

The Earth’s Revolution: Annual The Earth’s Revolution: Annual MotionMotion

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The reasons for seasons – the Earth travels around the sun, and its axis of rotation is tilted by 23.5 degrees to the plane of the orbit. In July, the northern hemisphere is getting more sunlight than in January.

The heliocentric model

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Earth’s tilt causes seasonsEarth’s tilt causes seasons

Note typo “rotation”

??

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Summer: Earth tilted toward the Summer: Earth tilted toward the sunsun

More concentrated light when the More concentrated light when the sun is higher in the sky (fig 1-14)sun is higher in the sky (fig 1-14)

Time the sun is up is longer: rises Time the sun is up is longer: rises farthest north on summer solsticefarthest north on summer solstice

Southern hemisphere: opposite Southern hemisphere: opposite seasonseason

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SunlightSunlight

and space traveland space travel

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DistancesDistances

If you drive on a highway at 60 k.m.s per hourIf you drive on a highway at 60 k.m.s per hour in one hour you may get to Hiriyuru.in one hour you may get to Hiriyuru. Steady speed!Steady speed!

If you keep on driving after 4 hours you would reach If you keep on driving after 4 hours you would reach Bangalore.Bangalore. Steady speed - no stops!Steady speed - no stops!

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If we could keep on and on - - If we could keep on and on - -

If you could drive to the Moon If you could drive to the Moon

at 70 miles per hour,at 70 miles per hour,

230,000 miles or about 400,000 km230,000 miles or about 400,000 km

it would take you 3400 hours, it would take you 3400 hours, or 140 days.or 140 days.

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Light and heat Light and heat comes from the Suncomes from the Sun

It is a long way awayIt is a long way away ! ! 146 million km or 93 million miles146 million km or 93 million miles

If you could drive to the Sun at 70 miles per hourIf you could drive to the Sun at 70 miles per hour

it would take over 50 000 days.it would take over 50 000 days. = = 150 years150 years

–– longer than we livelonger than we live !!

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Light travels very, very fast!Light travels very, very fast!

Guess how long it takes for light to Guess how long it takes for light to

come from the SUN to the Earth.come from the SUN to the Earth.

8 years8 years 8 days8 days 8 hours8 hours 8 minutes8 minutes

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It takesIt takes

8 minutes8 minutes

for light to reach us from the Sun!for light to reach us from the Sun!

Light travels 300 000 kilometres through space every second!

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ShadowsShadows

Light travels in a straight line.Light travels in a straight line.

If something gets in its path the light is If something gets in its path the light is blocked.blocked.

A shadow is formed.A shadow is formed.

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ShadowsShadows

How do How do they form?they form?

Sun

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We can make shadowsWe can make shadows !!

- by blocking out the light.

Changing positions varies the size of the shadow.

If you are close to the lamp, the shadow is large.

If you are close to the screen, the shadow is smaller.

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Day and NightDay and Night

A day + a night = 24 hoursA day + a night = 24 hours

365 of these makes 1 year.365 of these makes 1 year.

The Earth takes 1 year to orbit the Sun.The Earth takes 1 year to orbit the Sun.

(What does ‘orbit’ mean?)(What does ‘orbit’ mean?)

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The Earth is a ball (or sphere)The Earth is a ball (or sphere)

The Sun cannot shine on both sides of the Earth at The Sun cannot shine on both sides of the Earth at the same timethe same time

Some of the Earth is bright - daySome of the Earth is bright - day Some is dark – nightSome is dark – night The Earth spins so each part has day and night.The Earth spins so each part has day and night.

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Day and nightDay and night

Daylight in the UKDaylight in the UK

Light from the Sun

Dark in China

Dusk in India

Light Dark

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At midday hereAt midday here

It is dawn in the USAIt is dawn in the USA It is dusk in IndiaIt is dusk in India

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As the Earth spins As the Earth spins the position of the Sun varies.the position of the Sun varies.

Morning – the sun rises - it is light.Morning – the sun rises - it is light. The Sun gets higher in the sky.The Sun gets higher in the sky. Then the Sun sinks and sets.Then the Sun sinks and sets.

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Shadows move during the dayShadows move during the day Watch the shadow of the stickWatch the shadow of the stick

to tell the timeto tell the time like a sundial.like a sundial.

stick

6.00 pm

12.00 noon

6.00 am

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The seasons:The seasons: the Sun provides light and heatthe Sun provides light and heat but -but -

winter is coldwinter is cold

summer is warmersummer is warmer

What causes this?What causes this?

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The Four SeasonsThe Four Seasons

INFANT JESUS SCHOOLINFANT JESUS SCHOOL

Next Slide

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SeasonsSeasons

What do your students think causes the seasons?What do your students think causes the seasons?

http://nix.ksc.nasa.gov/info

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True color imagesTrue color images

June

December March

September

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What Causes Earth’s Seasons?What Causes Earth’s Seasons?

Earth’s axis is tilted 23.5 degrees – it always points in Earth’s axis is tilted 23.5 degrees – it always points in the same direction (Polaris, the North Star) as we the same direction (Polaris, the North Star) as we orbit our Sun once a yearorbit our Sun once a year

This tilt causes the hemispheres to alternate in the This tilt causes the hemispheres to alternate in the amount of our Sun’s light and heat they receive amount of our Sun’s light and heat they receive through the yearthrough the year

http://www.lpi.usra.edu/education/skytellers/seasons/about.shtml

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Earth’s tilt causes seasonsEarth’s tilt causes seasons

Note typo “rotation”

??

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More daylight hours, more direct sunlight

Northern Hemisphere Northern Hemisphere SummerSummer

INFANT JESUS HIGH SCHOOL, CHALLAKERE

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Earth’s orbit is Earth’s orbit is almostalmost a perfect a perfect circlecircle

• Earth is CLOSEST to our Sun (91 million miles) in winter—January 3

• Earth is farthest from on our Sun (94 million miles) in summer –July 4

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Height of SunHeight of Sun

Winter: The Sun rises in the southeast, stays low in the sky, and sets in the southwest.

Spring: The Sun rises due east, moves higher in the sky than in winter, and sets due west.

Summer: The Sun rises in the northeast, travels high (near zenith), and sets in the northwest.

Fall: The Sun rises due east, travels to a medium-height in the sky, and sets due west.

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SeasonSeasonss

higher=> more intense

p. 21 fig 1-14

Solar efficient design

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Winter Winter Winter is the coldest season.Winter is the coldest season. In the winter, it snows. In the winter, it snows. North pole is inclined away from the sun from 22North pole is inclined away from the sun from 22ndnd of December. of December. So the Northern Hemisphere enjoys winter season and Southern So the Northern Hemisphere enjoys winter season and Southern

Hemisphere the summer seasons.Hemisphere the summer seasons. Nights are longer, days are shorter in the Northern HemisphereNights are longer, days are shorter in the Northern Hemisphere At the same time in the Southern Hemisphere, the days are longer At the same time in the Southern Hemisphere, the days are longer

and the nights shorter.and the nights shorter. On December 22On December 22ndnd, there is 24 hour night at the north pole & 24 , there is 24 hour night at the north pole & 24

hour day at the south pole.hour day at the south pole. During the winter there is no vegetation and the animals hibernate.During the winter there is no vegetation and the animals hibernate. The winter is great for making snowmen.The winter is great for making snowmen.

Next Slide

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Sun lower in sky in winterSun lower in sky in winter

Looking south Dec 21

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SpringSpring

The vertical rays of the sun fall on the The vertical rays of the sun fall on the equator on March 21equator on March 21stst, days & nights are , days & nights are equal throughout the world. equal throughout the world.

It is spring in the Northern Hemisphere & It is spring in the Northern Hemisphere & autumn in the Southern Hemisphere.autumn in the Southern Hemisphere.

Flowers begin to peak their heads above Flowers begin to peak their heads above the ground.the ground.

Next Slide

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Summer Summer The summer is the hottest season.The summer is the hottest season. North pole is inclined towards the sun. So the Northern Hemisphere North pole is inclined towards the sun. So the Northern Hemisphere

enjoys summer & Southern Hemisphere enjoys winter.enjoys summer & Southern Hemisphere enjoys winter. Days are longer, nights are shorter in Northern Hemisphere.Days are longer, nights are shorter in Northern Hemisphere. In Southern Hemisphere days are shorter & nights are longerIn Southern Hemisphere days are shorter & nights are longer On June 21On June 21stst there is exactly 24 hour day at the north pole and 24 there is exactly 24 hour day at the north pole and 24

hour night at the south pole.hour night at the south pole. The vegetation is fully bloomed and the animals are very active.The vegetation is fully bloomed and the animals are very active. Summer is great for swimming.Summer is great for swimming.

Next Slide

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Summer: Earth tilted toward the Summer: Earth tilted toward the sunsun

More concentrated light when the More concentrated light when the sun is higher in the sky (fig 1-14)sun is higher in the sky (fig 1-14)

Time the sun is up is longer: rises Time the sun is up is longer: rises farthest north on summer solsticefarthest north on summer solstice

Southern hemisphere: opposite Southern hemisphere: opposite seasonseason

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AutumnAutumn

The vertical rays of the sun fall on Equator The vertical rays of the sun fall on Equator on 23on 23rdrd of September. of September.

The duration of days & nights is equal The duration of days & nights is equal throughout the earth on this day.throughout the earth on this day.

When it is autumn in the Northern When it is autumn in the Northern Hemisphere, it is spring in the Southern Hemisphere, it is spring in the Southern Hemisphere.Hemisphere.

Next Slide

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In which season do the leaves In which season do the leaves begin to change colors?begin to change colors?

(Select the correct answer)(Select the correct answer)

Winter Spring

Summer Autumn

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This answer is incorrectThis answer is incorrect

Please review the lesson and then choose Please review the lesson and then choose the correct answer.the correct answer.

Click to repeat question

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Correct!!!!Correct!!!!

The leaves begin to change colors and fall The leaves begin to change colors and fall off the trees in autumn.off the trees in autumn.

Next Slide

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Summer and winterSummer and winter

In winter the Sun stays low in the sky.In winter the Sun stays low in the sky. In summer the Sun rises higher in the sky.In summer the Sun rises higher in the sky.

Winter

Summer

The horizon

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Summer and winterSummer and winter The earth is tipped as it spinsThe earth is tipped as it spins

Light and heat reach the Earth at different angles in summer and winterLight and heat reach the Earth at different angles in summer and winter

In winter the light and heat from the Sun is more spread out than during the In winter the light and heat from the Sun is more spread out than during the Summer.Summer.

It feels colderIt feels colder

We can try an experiment.We can try an experiment.

Sun

Summer

Winter

Beam of light

Earth

Earth

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Leap yearLeap year

Earth requires 365 ¼ days to complete Earth requires 365 ¼ days to complete one revolution. one revolution.

The year is calculated for 365 days.The year is calculated for 365 days.The difference of ¼ day is adjusted once The difference of ¼ day is adjusted once

in 4 years and that year has 366 days. \in 4 years and that year has 366 days. \ It is called a leap year.It is called a leap year.During leap year, February has 29 days.During leap year, February has 29 days.

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EffectsEffects

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What have we learned?What have we learned? (Sunlight takes 8 minutes to reach the Earth.)(Sunlight takes 8 minutes to reach the Earth.)

Shadows form when light is blocked out.Shadows form when light is blocked out.Night is when no sunlight reaches us.Night is when no sunlight reaches us.We can tell the time by shadows.We can tell the time by shadows. In winter the Sun is low in the sky.In winter the Sun is low in the sky.The moon reflects light to the Earth.The moon reflects light to the Earth. Its shape changes because of shadows.Its shape changes because of shadows.

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equinoxes and equinoxes and solsticessolsticesEquinox:Equinox:

‘‘equal night’: 12 hours daylightequal night’: 12 hours daylightSun’s rays are overhead at the equator on Sun’s rays are overhead at the equator on

March 21 & Sep 23March 21 & Sep 23rdrd On these days the day & nights are of equal On these days the day & nights are of equal

duration throughout the world.duration throughout the world.These days are called equinoxesThese days are called equinoxesSun rises due east, sets due westSun rises due east, sets due west

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sunlight

sunlight

Vernal Equinox – 21 March

equator

antarcticcircle

arcticcircle

tropic ofCancer

tropic ofCapricorn

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SolisticesSolistices

Sun’s rays fall vertically over the tropic of cancer Sun’s rays fall vertically over the tropic of cancer & the sun appears stands still at this position & the sun appears stands still at this position and further moves towards the equator.and further moves towards the equator.

On sept 23On sept 23rdrd, the sun’s rays fall vertically over , the sun’s rays fall vertically over the tropic of capricorn. the tropic of capricorn.

The position of 22The position of 22ndnd June is called Summer June is called Summer Solstice in the Northern Hemisphere & 23Solstice in the Northern Hemisphere & 23rdrd of of Sept is called winter solstice.Sept is called winter solstice.

Means marking of winter in Northern Means marking of winter in Northern HemisphereHemisphere

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equinoxes and equinoxes and solsticessolstices

SolsticesSolstices:: “sun stops” and heads back “sun stops” and heads back

Summer solstice: June 21/22Summer solstice: June 21/22 longest number of daylight hours, longest number of daylight hours, sun sets farthest north, rises farthest northsun sets farthest north, rises farthest northmost concentrated sunlightmost concentrated sunlight

Winter Solstice: Dec 21/22Winter Solstice: Dec 21/22

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p. 23

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Keep asking Keep asking questions!questions!

There is lots to find out!There is lots to find out!

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JEOPARDY !Rules --->

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Each team will need a scorekeeper --->

1. Each team will get a turn. 2-3 teams.

2. Each question is worth 3 points.

3. If a team misses a question, they forfeit 1 point.

4. The QUESTION to each ANSWER is either rotation or

revolution.

5. Each answer must be in the form of a QUESTION.

6. Applause = Correct Explosion = Incorrect

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1. The Earth spinning on its axis. Rotation

Revolution2. Going around a larger body. Rotation

Revolution

Revolution

4. Causes the Earth’s seasons. RevolutionRotation

5. Creates a year.

3. 24 hours. Rotation

Revolution

RevolutionRotation

6. The moon going around Earth. RevolutionRotation

Go on to Round Two --->

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Identify the motion being shown in each of these pictures. Each team must write their answers for

each figure in the form of a question.

Earth

Figure #1 Rotation

Revolution

Figure #2

Rotation

Revolution

Final Round --->

Planet

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Each team must confer and write the

amount of points they would like to risk on

the Final Round - The topic is Seasons.

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XCLICK HERE FOR A FINAL MESSAGEWhich team had most points? You’re all

WINNERS!!!

SUN

Identify the Season being

shown in this

picture.--->

Winter FallSummerSpring

Choose the correct tree--

>

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Earth Patterns,Cycles, and Earth Patterns,Cycles, and ChangeChange

The sun heats the Earth The sun heats the Earth unevenly, making the poles unevenly, making the poles cold and the tropics hot, cold and the tropics hot, because-because-

A the tropics face more directly A the tropics face more directly

toward the suntoward the sun B the poles are covered with ice B the poles are covered with ice

which causes cold airwhich causes cold air C seasons changeC seasons change D weather changesD weather changes

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The moon revolves around -The moon revolves around -

FF itselfitselfGG the Earththe EarthHH the sunthe sunJJ the solar systemthe solar system

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The moon revolves or The moon revolves or orbits the Earth once orbits the Earth once every 29 days.every 29 days.

We all ways see the We all ways see the same side of the same side of the moon because the moon because the moon rotates and moon rotates and revolves at about the revolves at about the same speed.same speed.

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Earth Science Question: Earth Science Question: rotationrotation

What is rotation? (define)What is rotation? (define)

The rotation of the Earth on its axis The rotation of the Earth on its axis causes-causes-AA daysdaysBB monthsmonthsCC seasonsseasonsDD yearsyears

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Rotation causes day & night.Rotation causes day & night.

Rotation is the turning Rotation is the turning or spinning of the or spinning of the Earth in one place on Earth in one place on its imaginary axis.its imaginary axis.

Rotation of the earth Rotation of the earth on its axis causes day on its axis causes day & night. (answer A).& night. (answer A).

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Earth Science Question: Earth Science Question:

Which of these Which of these shows the location shows the location of a polar ice cap?of a polar ice cap?

Which of these Which of these shows the location shows the location of the equator?of the equator?

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Polar ice caps= APolar ice caps= A

Equator= C Equator= C

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Which of these is caused by the Which of these is caused by the turning of the Earth?turning of the Earth?

FF Summer and winterSummer and winterGG StarsStarsHH Day and nightDay and nightJJ Moon phasesMoon phases

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The turning of the Earth causesThe turning of the Earth causes

Day & Day & NightNight

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When the moon is seen from When the moon is seen from the Earth as a whole circle, it is the Earth as a whole circle, it is

called a-called a-

AA Crescent moonCrescent moonBB Full moonFull moonCC Half moonHalf moonDD New moonNew moon

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When the moon is seen from the When the moon is seen from the Earth as a whole circle, it is called aEarth as a whole circle, it is called a

FULL MOON.FULL MOON.

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Which of these is the next Which of these is the next phase of the moon?phase of the moon?

New Moon --- Waxing Crescent --- ?New Moon --- Waxing Crescent --- ?

F Full MoonF Full MoonG Waning CrescentG Waning CrescentH First QuarterH First QuarterJ Waxing GibbousJ Waxing Gibbous

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The next major phase of the The next major phase of the moon would be…moon would be…

First quarter.First quarter.

Just think about it…theJust think about it…the New moonNew moon (can only get (can only get

bigger. Or = Waxing)..bigger. Or = Waxing).. Then comes Then comes Waxing crescentWaxing crescent

…next is…next is First quarterFirst quarter…then …then Waxing GibbousWaxing Gibbous and then a and then a Full MoonFull Moon..

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The revolution of the Earth The revolution of the Earth around the Sun takes-around the Sun takes-

AA a day & night or 12 hoursa day & night or 12 hoursBB a week or 7 daysa week or 7 daysCC a month or 29-31 daysa month or 29-31 daysDD a year or 365 daysa year or 365 days

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The revolution of the Earth The revolution of the Earth around the sun around the sun

Takes 365 days Takes 365 days or one year.or one year.

NOTE:NOTE: Due to the tilt of the Due to the tilt of the

Earth’s axis during Earth’s axis during revolution, the Earth revolution, the Earth experiences seasons.experiences seasons.

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LATITUDES & LONGITUDESLATITUDES & LONGITUDES

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What is Latitude?What is Latitude?

Latitude is the distance from Latitude is the distance from thethe equator along the Y axis. equator along the Y axis.

All points along the equator All points along the equator have a value of 0 degrees have a value of 0 degrees latitude.latitude.

North pole = 90North pole = 90°N°N South pole = 90South pole = 90°S°S Values are expressed in Values are expressed in

terms of degrees.terms of degrees.

Y

X

90°S

90°N

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What is Latitude?What is Latitude? Each degree of latitude Each degree of latitude

is divided intois divided into 60 minutes. 60 minutes.

Each minute is divided Each minute is divided

into 60 secondsinto 60 seconds..

Y

X

90°S

90°N

This is also true of longitude.

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What is Latitude?What is Latitude?For Example:For Example:3737°, 02’,51’’N°, 02’,51’’NThis is close to This is close to

the latitude where the latitude where you live.you live.

Y

X

90°S

90°N

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What is Longitude?What is Longitude? Longitude is the Longitude is the

distance from the prime distance from the prime meridian along the X meridian along the X axis.axis.

All points along the All points along the prime meridian have aprime meridian have a value of 0 degrees value of 0 degrees longitude.longitude.

The earth is divided into The earth is divided into two parts, ortwo parts, or hemispheres, of east hemispheres, of east and west longitude.and west longitude.

Y

X

180°W 180°E

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What is Longitude?What is Longitude?The earth is The earth is

divided into 360 divided into 360 equal slicesequal slices (meridians) (meridians)

180 west and 180 180 west and 180 east of the prime east of the prime meridianmeridian

Y

X

180°W 180°E

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What is Latitude?What is Latitude?Our latitude and Our latitude and

longitude might longitude might be:be:

3737°, 03’,13’’N°, 03’,13’’N76°, 29’, 45’’W76°, 29’, 45’’W

Y

X

90°S

90°N

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So Where is (0,0)?So Where is (0,0)?The origin point The origin point

(0,0) is where (0,0) is where the equator the equator intersects theintersects the prime prime meridian.meridian.

(0,0) is off the (0,0) is off the western coast of western coast of Africa in the Africa in the Atlantic Ocean.Atlantic Ocean.

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See If You Can Tell In Which Quarter These See If You Can Tell In Which Quarter These Lon/Lats Are LocatedLon/Lats Are Located

1. 411. 41°N, 21°E°N, 21°E2. 37°N, 76°W2. 37°N, 76°W3. 72°S, 141°W3. 72°S, 141°W4. 7°S, 23°W4. 7°S, 23°W5. 15°N, 29°E5. 15°N, 29°E6. 34°S, 151°E6. 34°S, 151°E

A B

C D

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1. B 1. B 2. A2. A3. C3. C4. C4. C5. B5. B6. D6. D

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LatitudeLatitude ( (shown as a horizontal lineshown as a horizontal line) is ) is the angular distance, in degrees, minutes, the angular distance, in degrees, minutes, and seconds of a point north or south of and seconds of a point north or south of the Equator. Lines of latitude are often the Equator. Lines of latitude are often referred to as parallels. referred to as parallels.

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Any location on Earth is described by two numbers--its latitude and its longitude. If a pilot or a ship's captain wants to specify position on a map, these are the "coordinates" they would use.     Actually, these are two angles, measured in degrees, "minutes of arc" and "seconds of arc." These are denoted by the symbols ( °,   ',   "  ) e.g. 35° 43' 9" means an angle of 35 degrees, 43 minutes and 9 seconds (do not confuse this with the notation (', ") for feet and inches!). A degree contains 60 minutes of arc and a minute contains 60 seconds of arc--and you may omit the words "of arc" where the context makes it absolutely clear that these are not units of time.

   

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Calculations often represent angles by small letters of Calculations often represent angles by small letters of the Greek alphabet, and that way latitude will be the Greek alphabet, and that way latitude will be represented by λ (lambda, Greek L), and longitude by φ represented by λ (lambda, Greek L), and longitude by φ (phi, Greek F). Here is how they are defined. (phi, Greek F). Here is how they are defined.

        Imagine the Earth was a Imagine the Earth was a transparent spheretransparent sphere (actually (actually the shape is slightly oval; because of the Earth's rotation, the shape is slightly oval; because of the Earth's rotation, its equator bulges out a little). Through the transparent its equator bulges out a little). Through the transparent Earth (drawing) we can see its equatorial plane, and its Earth (drawing) we can see its equatorial plane, and its middle the point is O, the center of the Earth. middle the point is O, the center of the Earth.

To specify the latitude of some point P on the surface, To specify the latitude of some point P on the surface, draw the radius OP to that point. Then the draw the radius OP to that point. Then the elevation elevation angleangle of that point of that point above the equatorabove the equator is its latitude λ-- is its latitude λ--northern latitude if north of the equator, southern (or northern latitude if north of the equator, southern (or negative) latitude if south of it. negative) latitude if south of it.

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LATITUDELATITUDE         Imagine the Earth was a Imagine the Earth was a transparent spheretransparent sphere (actually (actually

the shape is slightly oval; because of the Earth's rotation, the shape is slightly oval; because of the Earth's rotation, its equator bulges out a little). Through the transparent its equator bulges out a little). Through the transparent Earth (drawing) we can see its equatorial plane, and its Earth (drawing) we can see its equatorial plane, and its middle the point is O, the center of the Earth. middle the point is O, the center of the Earth.

To specify the latitude of some point P on the surface, To specify the latitude of some point P on the surface, draw the radius OP to that point. Then the draw the radius OP to that point. Then the elevation elevation angleangle of that point of that point above the equatorabove the equator is its latitude λ-- is its latitude λ--northern latitude if north of the equator, southern (or northern latitude if north of the equator, southern (or negative) latitude if south of it. negative) latitude if south of it.

      

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Latitude angleLatitude angle Lines of latitudeLines of latitude

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[How can one define the angle between a line and a [How can one define the angle between a line and a plane, you may well ask? After all, angles are usually plane, you may well ask? After all, angles are usually measured between two measured between two lineslines! !   Good question. We must use the angle which   Good question. We must use the angle which completes it to 90 degrees, the one between the given completes it to 90 degrees, the one between the given line and one line and one perpendicularperpendicular to the plane. Here that to the plane. Here that would be the angle (90°-λ) between OP and the Earth's would be the angle (90°-λ) between OP and the Earth's axis, known as the axis, known as the co-latitudeco-latitude of P.] of P.]

        On a globe of the Earth, lines of latitude are circles of On a globe of the Earth, lines of latitude are circles of different size. The longest is the different size. The longest is the equatorequator, whose latitude , whose latitude is zero, while at the poles--at latitudes 90° north and 90° is zero, while at the poles--at latitudes 90° north and 90° south (or -90°) the circles shrink to a point. south (or -90°) the circles shrink to a point.

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LONGITUDELONGITUDE

LongitudeLongitude ( (shown as a vertical lineshown as a vertical line) is the ) is the angular distance, in degrees, minutes, and angular distance, in degrees, minutes, and seconds, of a point east or west of the seconds, of a point east or west of the Prime (Prime (GreenwichGreenwich) Meridian. Lines of ) Meridian. Lines of longitude are often referred to as longitude are often referred to as meridians. meridians.

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On the globe, lines of constant longitude On the globe, lines of constant longitude ("meridians") extend ("meridians") extend from pole to polefrom pole to pole, , like the segment boundaries on a peeled like the segment boundaries on a peeled orange. orange.

      

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Every meridian must Every meridian must cross the equator. Since cross the equator. Since the equator is a circle, we the equator is a circle, we can divide it--like any can divide it--like any circle--into 360 degrees, circle--into 360 degrees, and the and the longitude φ of a longitude φ of a pointpoint is then the marked is then the marked value of that division value of that division where its meridian meets where its meridian meets the equator. the equator.

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A lines of longitude is also called a A lines of longitude is also called a meridianmeridian, , derived from the Latin, from derived from the Latin, from merimeri, a variation of , a variation of "medius" which denotes "middle", and "medius" which denotes "middle", and diemdiem, , meaning "day." The word once meant "noon", meaning "day." The word once meant "noon", and times of the day before noon were known as and times of the day before noon were known as "ante meridian", while times after it were "post "ante meridian", while times after it were "post meridian." Today's abbreviations meridian." Today's abbreviations a.m.a.m. and and p.m.p.m. come from these terms, and the Sun at noon come from these terms, and the Sun at noon was said to be "passing meridian". All points on was said to be "passing meridian". All points on the same line of longitude experienced noon the same line of longitude experienced noon (and any other hour) at the same time and were (and any other hour) at the same time and were therefore said to be on the same "meridian line", therefore said to be on the same "meridian line", which became "meridian" for short. which became "meridian" for short.

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Equator Latitude 0o

Latitude: (90oN to 90oS)

Latitude 23½o NorthTropic of Cancer

Latitude 23½o SouthTropic of Capricorn

Longitude 30o East

Longitude 60o East

Longitude 30o West

Longitude 60o West

Positioning on the Earth’s SurfaceEast is the direction of

rotation of the Earth North Pole

South Pole

23½o 23½o

66½o 90o

900

21st June

22nd December

22nd Sept

20th March

30oE60oE90oE90oW30oW60oW

Longitude 90oEastLongitude 90o West

Prime Meridian

0o Longitude

Longitude: (180oE to 180oW)

Latitude and Longitude together enable the fixing of position on the Earth’s surface.

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See if you See if you can find those can find those

same same latitude/longitlatitude/longitude locations ude locations

on a map!on a map!

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Now you’re ready to find some Now you’re ready to find some locations on a map!locations on a map!

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Longtitude & TimeLongtitude & Time

Earth rotates on its own axis & takes 4 Earth rotates on its own axis & takes 4 minutes to rotate to one degree of minutes to rotate to one degree of longitude and one hour to rotate 15 degree longitude and one hour to rotate 15 degree of longitudes.of longitudes.

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Local timeLocal time

When the sun is overhead on a particular When the sun is overhead on a particular longitude it is 12 noon at all the places longitude it is 12 noon at all the places located on that longitude.located on that longitude.

One degree longitude on either side of this One degree longitude on either side of this longitude will be 4 minutes behind on its longitude will be 4 minutes behind on its west and 4 minutes ahead on its east.west and 4 minutes ahead on its east.

It is known as local time.It is known as local time.There are 360 degrees longitudes, so There are 360 degrees longitudes, so

there are 360 local times.there are 360 local times.

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Standard TimeStandard Time

Local time cannot be used by railways, Local time cannot be used by railways, telegraphs & other international offices.telegraphs & other international offices.

In such cases the Standard Time is used.In such cases the Standard Time is used.The longitude which passes in the centre The longitude which passes in the centre

of a particular nation is known as Standard of a particular nation is known as Standard meridian.meridian.

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