OUR PLANET, THE EARTH

The Earth’s Features

• Its atmosphere contains oxygen.• Its average temperature is 15 ºC.• Water: solid, liquid, gas: water cycle.• A natural satellite: The Moon tides.• Magnetic field: protects from solar radiations.• Geological activity.• Life exists.

RotationRevolution

MOVEMENTS OF THE EARTH

Rotation Movement

• Is the spinning of the Earth on its axis.

• The time for one rotation is 24 hours.

• The speed of rotation is about 1.700 Km/h at the Equator.

Rotation consequences

Day and Night

http://www.juntadeandalucia.es/averroes/~29701428/ccnn/flash/tierra.swf

Revolution Movement

• It is our planet’s movement around the Sun.• It describes an eliptical orbit.• It takes 365 days to complete a revolution.

Revolution consequences

June 21stDecember21st

September 22nd

March 20th

The Seasons

http://www.juntadeandalucia.es/averroes/~29701428/ccnn/flash/tierra.swfhttp://www.juntadeandalucia.es/averroes/~29701428/ccnn/flash/fase_estaciones.swf

THE MOON

• It is our only natural satellite.• It was formed at the same time than the Earth.• It rotates (its days takes 29 terrestrial days).• It orbits the Earth at 3.680 Km/h.• It takes about 28 days to orbit the Earth.• It has no atmosphere, so it suffers lots of impacts,

which can form craters.

Las Fases de la Luna

http://rincones.educarex.es/byg/index.php/1-eso-la-tierra-en-universo/animaciones?showall=1&limitstart=

THE EARTH’S SPHERES

GEOSPHERE

• Is the solid (rocky) part of Earth. • We can distinguish three parts in it:

– Crust.– Mantle.– Core.

HIDROSPHERE

• Is all the water on, under and above the Earth:– Solid (ice).– Gas (water vapour).– Liquid: salty / fresh.

ATMOSPHERE

• The layer of air which sorrounds the Earth.– It contains the oxygen we breath.– It blocks dangerous solar radiations: UV.– It keeps an adequated temperature for life.

BIOSPHERE

• All the living things which inhabit the Earth.

LA SUPERFICIE TERRESTRE

• Relieve Continental:– Cadenas Montañosas (cordilleras).– Llanuras.– Plataformas continentales.

RELIEVE SUBMARINO

• Cordilleras oceánicas.• Fosas marinas.• Llanuras abisales.• Volcanes submarinos.