4 TH EVALUATION

 The sun is the largest cellestial body. It is the centre of the solar system. 1. What it the Sun?

2. What are the planets?  Large cellestial bodies that orbit around the sun. They are divided into two groups: GAS GIANTS: Jupiter, Saturn, Uranus and Neptune. THEY ARE LARGE AND MADE OF GAS TERRESTRIAL: Mercury, Venus, Earth and Mars THEY ARE MAINLY MADE UP OF ROCK.

3. Movements of the Earth  AROUND THE SUN  The earth revolves around the sun. It´s orbit is an elongated circle, called ELLIPSE.  It takes the earth exactly 365 days and 6 hours.  ROTATION OF THE EARTH  The earth is a sphere, and it rotates on its own invisible axis.  It takes exactly 24 hours to complete this rotation.

4. Why the seasons?  The Earth´s axis is slightly tilted. At any time one hemisphere is tilted towards the sun, receiving more light and heat, while the other one is tilted away from the sun, it receives less light and heat.

5. Tell me the 4 Lunar phases  When we look at the moon to earth, its appearance changes. These are the lunar phases 1. NEW MOON2. FIRST QUARTER No part of the moon is One half of the moon is being lit visible because is not being by direct sunlight. lit by the Sun. 3. FULL MOON4. LAST QUARTER The side of the earth facingThe other half of the moon is being the Earth is being lit.lit by direct sunlight.

6. Types of Eclipses.  Sometimes the Moon, the Earth and the Sun align and an Eclipse occurs.  LUNAR ECLIPSE:  The Earth passes between the Sun and the Moon.  SOLAR ECLIPSE:  The Moon passes between the Earth and the Sun.

LUNAR ECLIPSE

SOLAR ECLIPSE

7. Stars, Characteristics.  STARS: Spherical bodies which generates light and heat through nuclear reactions.  They have three characteristics: COLOURSIZELUMONISITY Depending on their temperature. All are enormous, but some are bigger than others. Amount of light that the star has.

8. Galaxies  They are enormous groups of stars, gases and dust.  There are three types: ELLIPTICALSPIRALIRREGULAR