THE PLANET EARTHTHE PLANET EARTH

Science 1º ESO – Unit 2Science 1º ESO – Unit 2

© I.E.S. “Luis de Góngora” (Córdoba); Dept. Biology and Geology© I.E.S. “Luis de Góngora” (Córdoba); Dept. Biology and Geology

Juan Manuel Barroso Fernández Juan Manuel Barroso Fernández

Bilingual Educational Project.Bilingual Educational Project.

We are about to start a trip through We are about to start a trip through the Milky Way, looking for the Earth!the Milky Way, looking for the Earth!

Photo: cosmos4kids.com

Planet EarthPlanet Earth

SunSun

This is our planet, the EARTHThis is our planet, the EARTH

Earth is the Earth is the thirdthird planet planet in our in our SolarSolar System System

That, in turn, is located in That, in turn, is located in the galaxy “the galaxy “Milky WayMilky Way””• The Earth is 12,756 km

in diameter

• It is 1.5 million km from the Sun

Photo of the Earth: cnice

THE EARTH’S MOTIONSTHE EARTH’S MOTIONS

The Earth moves in two The Earth moves in two different ways:different ways:

Earth rotationEarth rotationEarth revolutionEarth revolution

Earth rotation:Earth rotation:It spins around It spins around

its own axis its own axis every every 24 hours24 hours

The spinning gives The spinning gives rise to rise to nightnight and and dayday

Photo of the Earth: cnice

It occurs on a plane called the It occurs on a plane called the “ecliptic plane”“ecliptic plane”

Its Its orbit has an orbit has an ellipticalelliptical shape and the shape and the Sun is placed in Sun is placed in one one of the two focuses.of the two focuses.

The rotation axis has an angle of The rotation axis has an angle of 23.5 23.5 degreesdegrees in relation to the perpendicular in relation to the perpendicular axis of the ecliptic plane.axis of the ecliptic plane.

It revolves around the Sun, each It revolves around the Sun, each revolution having a period of a revolution having a period of a yearyear..

THE EARTH’S MOTIONSTHE EARTH’S MOTIONSEarth revolution:Earth revolution:

23.5º23.5º

Photo of the Earth: cnice

SEASONSSEASONS As a consequence of revolution and this As a consequence of revolution and this

inclination, the Earth has seasons.inclination, the Earth has seasons. In our hemisphere each season starts on…In our hemisphere each season starts on…

Spring Equinox: 21st March

Autumn Equinox: 22nd September

Summer Solstice:

21st June

Winter Solstice:

22nd December

Photo of the Earth: cnice

ATMOSPHEREATMOSPHERE

HYDROSPHEREHYDROSPHERE

BIOSPHEREBIOSPHERE

Photo of the Earth: cnice

It is the aqueous layer. It’s made

up of liquid and solid water

OUR PLANET HAS FOUR LAYERS…OUR PLANET HAS FOUR LAYERS…It is the rocky part of the Earth

It is the gaseous layer that surrounds

the Earth. Its made up of air

It is all living things

GEOSPHEREGEOSPHERE

CRUSTCRUST

UPPER MANTLEUPPER MANTLELOWER MANTLE

OUTER COREOUTER COREINNER COREINNER CORE

The crustThe crust is the is the first rocky layer. first rocky layer.

It’s made up of It’s made up of granite and granite and basaltbasalt

The mantleThe mantle is is located below located below the crust, the crust, between 35 between 35 and 2,900 kmand 2,900 km

The coreThe core is is the deepest the deepest layer. It’s layer. It’s made up of made up of ironiron

Photo of the Earth: cnice

The Moon is the Earth’s SatelliteThe Moon is the Earth’s Satellite

The Moon is the only The Moon is the only satellite of the Earth.satellite of the Earth.

Main CharacteristicsMain Characteristics It is 3,760 km in It is 3,760 km in

diameterdiameter It is located 384,400 It is located 384,400

km from the Earthkm from the Earth

Photo of the Moon: cnice

The Moon’s MotionsThe Moon’s MotionsIt has TWO different movements:

1. ROTATION: with a 28-day period2. REVOLUTION: also with a 28-day period

As a consequence of these synchronized movements…

The moon is always addressing us The moon is always addressing us with the with the SAME FACESAME FACE

Photo of the Moon: cnice

Seen from Earth, the Seen from Earth, the Moon’s look varies Moon’s look varies according to its position according to its position in the orbit…in the orbit…

The Moon seen from Earth:

Photo of the Moon: cnice

NEW Moon

FIRST QUARTER Moon

THIRD QUARTER Moon

FULL Moon

This way, LUNAR PHASESLUNAR PHASES are distinguished:

The Moon seen from Earth:

ECLIPSESECLIPSESAn eclipse occurs when the Earth, An eclipse occurs when the Earth,

the Moon and the Sun form the Moon and the Sun form a linea line::

If the If the MoonMoon comes into the Earth’s comes into the Earth’s shade, a shade, a lunar eclipselunar eclipse takes place. takes place.

If the If the EarthEarth comes into the Moon’s comes into the Moon’s shade, a shade, a solar eclipsesolar eclipse takes place. takes place.

SOLAR ECLIPSESOLAR ECLIPSE

A solar eclipse occurs when the Moon is A solar eclipse occurs when the Moon is in the middle.

This means that the Moon has to be a This means that the Moon has to be a New MoonNew Moon..

NEW Moon

LUNAR ECLIPSELUNAR ECLIPSE

A lunar eclipse occurs when the Earth is A lunar eclipse occurs when the Earth is in the middlein the middle..

This means that the Moon has to be a This means that the Moon has to be a Full MoonFull Moon..

FULL Moon

Why aren’t there Why aren’t there eclipses every eclipses every

month?month?

NEW Moon FULL Moon

This is the ecliptic plane (where the Earth revolves around the Sun)

5º5º

However, the Moon revolves around the Earth on a plane that forms a 5º angle with this plane…

… This is why we only can get an ECLIPSE:

- And, - And, at the same timeat the same time, the Earth, the Moon and the Sun , the Earth, the Moon and the Sun form a line.form a line.

- When the Moon is on the ecliptic plane

If the EARTH is in the middle…

A LUNAR ECLIPSE LUNAR ECLIPSE occurs.

If the MOON is in the middle…

A SOLAR ECLIPSE SOLAR ECLIPSE occurs.

The MOON is on the ECLIPTIC PLANEECLIPTIC PLANE

A SOLARSOLAR ECLIPSE occurs.

The Moon is between the Earth and the Sun (NEW Moon)

Ecliptic plane

The Earth is between the Moon and the Sun (FULL Moon)

The MOON is on the ECLIPTIC PLANEECLIPTIC PLANE

A LUNAR LUNAR ECLIPSE occurs.ECLIPSE occurs.

Ecliptic plane

The SUN, the EARTH and the MOON DO NOT FORM A LINEFORM A LINE

There IS NOT There IS NOT an ECLIPSE

Although the Moon is located on the ecliptic planeecliptic plane…

Ecliptic plane

Although the Moon is located BETWEENBETWEEN The Earth and the Sun, a New Moon…

…The Moon IS NOTIS NOT on the ECLIPTIC PLANEECLIPTIC PLANE

There IS NOTThere IS NOT an ECLIPSE an ECLIPSE

…or it is a Full Moon…