The Earth in the universe

• What models were proposed to explain the Earth´s position in the Universe?

Identify the model or theory

• It was proposed by Aristarchus de Samos and Copernicus.

• The Earth is in the centre of the Universe• It was verified by Galileo• It says that the Sun is in the centre of the

Universe• It was proposed by Aristotle and Ptolemy• 16th century

What units of measurement are used in astronomy?

• Light-year• Parsec• Astronomical units

Galaxies are made of:

• Stars…• Nebulae• Dust and gas

Our galaxy is

• The Milky Way• A spiral galaxy• Located in the galaxy cluster– The Local group

• The solar system is in the:– Orion arm

What do you know about stars?

• Do they emit light?• Why?• What happens when a star consumes the

hydrogen?

The Solar System

• What are the main celestial bodies?– Planets– Dwarf planets– Asteroids– Comets– Satellites

Where can we find?

• Asteroids?– Asteroid belt. Where is it?– Kuiper belt. Where is it?

• Comets?– Oort cloud

What movements have the planets?

• Rotation• Revolution

Compare the inner and the outer planets

• Composition• Closer or farther from the Sun• Low or high number of satellites• Atmosphere• Other things

What planet?

• Has no atmosphere?– Mercury

• The only planet where life has been found– The Earth

• It rotates in an opposite direction and has a dense atmosphere– Venus

• Is the largest?• Jupiter• Its well-known for its famous rings• Saturn• The farthest planet• Neptune• It has the Great red spot• Jupiter• The red planet• Mars

What causes the seasons on Earth?

• The movement of revolution• The tilt of the Earth´s axis

True or false

• In summer in the Northern hemisphere, the Sun rays strike the Earth perpendicular.

• In summer the solar rays hit the Earth at an angle in the northen hemisphere

• The axis of the Earth is tilted towards the Sun in Summer.

What are the phases of the Moon?

What is it?

https://www.youtube.com/watch?v=l37ofe9haMU