The Earth has several key features that support life, including an atmosphere containing oxygen, average temperatures of 15°C, and a water cycle. It rotates on its axis once every 24 hours, causing day and night, and revolves around the sun over the course of 365 days, causing the seasons. The moon orbits the Earth every 28 days and causes ocean tides. The Earth also has a molten iron core that generates a magnetic field protecting it from solar radiation.

1. OUR PLANET, THE EARTH

2. 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.

4. MOVEMENTS OF THE EARTH
Rotation
Revolution

5. 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.

6. Rotation consequences
Day and Night

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

8. Revolution consequences
June 21st
December
21st
September 22nd
March 20th
The Seasons

9. THE MOON

10. • 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.

11. Las Fases de la Luna

12. THE EARTH’S SPHERES

13. GEOSPHERE
• Is the solid (rocky) part of Earth.
• We can distinguish three parts in it:
– Crust.
– Mantle.
– Core.

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

15. 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.

16. BIOSPHERE
• All the living things which inhabit the Earth.

17. LA SUPERFICIE TERRESTRE
• Relieve Continental:
– Cadenas Montañosas (cordilleras).
– Llanuras.
– Plataformas continentales.

18. RELIEVE SUBMARINO
• Cordilleras oceánicas.
• Fosas marinas.
• Llanuras abisales.
• Volcanes submarinos.