1. PLANET EARTH1st ESO

Maira Gil CamarónSource: Santillana Richmond

The Earth and the Solar SystemThe Solar System

It consists in a single star (the Sun) and the planets that orbit it: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.

The Earth is the fifth biggest planet in the Solar System, with a surface of 510 km2. It is the third planet closest to the Sun

Most planets in the Solar System have one or more satellites. The Earth has only one: the Moon

The biosphere: life on Earth The Earth is the only planet in the Solar System where life

exists. This conditions make this possible: The ideal TEMPERATURE for life due to the right distance to the Sun The ATMOSPHERE, a layer or gases that protects the Earth from the

Sun’s radiation WATER, necessary for all living things

Biosphere: the ecological system in which life exists

The outer structure of the Earth It consists of three parts:

The Atmosphere is the layer of gases that surrounds the Earth: nitrogen, oxygen and carbon dioxide

The Hydrosphere is all the water that exists in our planet: oceans, seas, rivers, lakes, ice, groundwater and water vapour

The Lithosphere is the Earth’s solid outer layer. It consists of the continents and submerged land

The movements of the EarthRotation and

revolution Rotation: on its own

axis. The Earth rotates on its axis once a day, so it does one complete rotation every 24 hours As the Earth rotates, places

on the surface sometimes face the sun – this is day

When the face away from the sun, is is night

Revolution: around the Sun. The Earth orbits around the sun every 365 ¼ days, or once a year, in an elliptical orbit

Each year has four seasons, and there are season because the Earth’s axis is not vertical, it is tilted

The seasons In summer, one hemisphere

is tilted towards the sun and its rays reach the hemisphere almost vertically. At the same time, in the other hemisphere is winter because it is tilted away from the sun. In spring and autumn the Sun’s rays reach both hemispheres at a similar angle

Solstices: the Sun’s rays are vertical at one of the tropics. Days are long and warm in this hemisphere (21 June & 21 December)

Equinoxes: the Sun’s rays are vertical at the equator. Both hemisphere receive the same amount of sunlight and day and night are equally long (21 March & 23 September)

How is the Earth represented? Globes are the most

accurate way to represent the Earth. It is a small version of it because have similar shape of our planet

Maps show the Earth on a flat surface and can provide information about a small area, a country… or the whole world. When we make a flat map of the curved Earth, shapes and distances get distorted. A map has a title, a scale, a key, an arrow pointing north, and a grid of imaginary lines (parallels and meridians)

Establishing direction Cardinal points to establish direction: north, south, east and

west. You can use a compass, an instrument with a magnetic needle which always points north

Nature

What type of maps are there? Physical maps show the shape of the land, and water

features like seas and oceans. More detailed physical maps are called topographic maps because they also show heights, roads, rivers, place names

Political maps show the boundaries between countries or regions, towns and cities

Thematic maps show a specific thing: population, climate…

Physical map Political map Thematic map:Annual precipitations

How do we locate places on maps?

Parallels are imaginary lines running in an east-west direction. The Equator (0º) divides the Earth in two hemispheres. There are 90 parallels between the Equator and each pole. Other important parallels: Artic Circle, Tropic of Cancer, Tropic of Capricorn, Antartic Circle LATITUDE is the distance from a parallel to the Equeator and it measures in

degrees, minutes and seconds. Its values go from 0º to 90º

Meridians are imaginary lines running in a north-south direction from the North Pole to the South Pole. The prime meridian (0º) is also called the Greenwich meridian. There are 360 meridians, 180 in each hemisphere LONGITUDE is the distance from a meridian to the Greenwich meridian. It

measures in degrees, minutes and secons. Its values go from 0º to 180º

Direction – Maps normally show which way is north. If they don’t, north is at the top of the page

Scale – The scale bar shows how the distances on the map relate to real distances

Key – The key (or legend) tells us what the symbols on the map mean

Grid lines – The grid lines are the lines of latitude and longitude. They show exactly where places on the map are. The vertical coordinate tells us the latitude. The horizontal coordinate tells us the longitude

How to read a map

Reading coordinates For the latitude, look at

the vertical coordinate For the longitude, look

at the horizontal coordinate

The coordinates of London are: 52ºN, 0,1ºW

Using the scale

The scale bar shows how the distances on the map relate to real distances. It could be numeric or graphic, and you can write the scale in different ways:

1cm = 100km 1cm on the map is 100km 1:10,000,000 this is the same (1cm = 100km) because there are

10 million cm in 100km

To work out the real distance: Measure the distance with a ruler. Imagine the distance between

Cádiz and Málaga is 1,8cm in a map For a scale of 1cm=100km we calculate:

Real distance (in km) = map distance (in cm) x 100 1,8 x 100 = 180 km

Time zones As a result of the Earth’s rotation, it is daytime on

one side of the Earth when it is night-time on the other. Time zone were created to make the time around the world correspond to the position of the sun The Earths is divided into 24 time zones, which go from

pole to pole. Time zones are measured from the Greenwich meridian: If we go to East, we move the clock forward by one hour If we go to West, we move the clock back by one hour

Time zones are influenced by political factors Some countries have the same time across the whole country,

even though they are in more than one time zone Other countries have several time zones