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

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

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

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.