SCIENCE : INVESTIGATING THE EARTH AND THE UNIVERSE

 

INVESTIGATING THE EARTH AND

THE UNIVERSE

1. The Solar system  

1.1 The Sun

1.2 Planets
1.3 Natural satelites
1.4 Comets
1.5 Asteroids
1.6 Meteors

The Sun
 * A Star in the centre of the Solar System.


Planets
* Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto
   
1. Mercury

• the closest planet to the Sun.
• temperature can be over 300oC in teh day time.
• rotates on its own axis very slowly, making one full rotation every 59 Earth days.  

2. Venus

• the second planet from the Sun.
• the size of Venus about the same as Earth.
• always covered by a very thick cloud of carbon dioxide and acid vapour.
• the temperature is extremely high, even though Venus is twice as far from the Sun as Mercury and receives only a quarter as much as light.

3. Earth

• the third planet from the Sun.
• the fifth largest planet.
• is the only planet with oxygen and water.
• only planet which living things can survive and grow.
• it takes about 65 days to revolve around the Sun and rotates its own axis once every 24 hours.

4. Mars

• the fourth planet from the Sun.
• is also known as red Planets its surface is being covered with red dust.
• is a cold and lifeless planet.
• one revolution of Mars around the Sun takes 687 days.

5. Jupiter

• the largest planet in the solar system.
• the fifth planet from the Sun.
• the planet which has the shortest day in the solar system.
• has sixteen Natural satelites or Moon and takes about 12 years to revolve once around the sun.

6. Saturn

• the sixth planet from the Sun.
• it is surrounded by a system of rings which make it the most striking and beautiful planet when viewed through a telescope. 
• the second the largest planet in the solar system but it is lighter than a body of water of the same size. 
• the time taken for Saturn to revolve around the sun is around 29 years.
• Saturn rotates on its own axis once every 10.7 hours.

7. Uranus

• the seventh planet from the Sun.
• it is blue because it has cold gasses, mainly made up of hydrogen and helium.
• it has ring around it but it can't be seen because it is too thin and dim.

8. Neptune

• the eighth planet from the Sun.
• it's almost the twin of Uranus.
• it is a little heavier than Uranus and very slightly bigger.
• it is bluish-green
• Neptune consists mainly of ice with some rocks and gases and less atsmosphere.

9. Pluto

• the ninth planet from the Sun.
• it is smallest planet in the solar system.
• it is made of rocks and thin ice.
• it is dark and cold planet.
• its surface temperature can be as low as -230oC.
• this planet can be seen only through a telescope because it is so far away from Earth.  

Natural satelites

* Objects around the planets, the Moon is the Natural satellite of the Earth

Comets

* Ice and dust that orbit around the sun.

Meteors

* Rock or metal that orbit around the sun.

Asteroids

* Rock and metal which lie between the orbit of Mars and Jupiter.

Relative size and distance

1. Distance

* Earth to the Moon = Ratio 1

* Earth to the Sun    = Ratio 400

2. Size

* Moon = Ratio 1

* Earth  = Ratio 4

* Sun    = Ratio 400





Eclipse of Moon

Once in a while Earth's shadow falls on the Moon , temporarily blocking out the sunlight that causes it to shine. This is called a lunar eclipse. Just as in a solar eclipse, the phenomenon occurs when the Sun, Earth, and the Moon are arranged in a straight line. During a lunar eclipse, which can be seen at night, the Moon will become smaller and smaller- and the disappear-before it emerges hit by hit from Earth's shadow.

The word "eclipse" means "in the shadows". In an eclipse of the sun, sun, moon, and earth are all lined up, so that the moon's shadow falls on the Earth. In an eclipse of the moon, it is the shadow of the Earth that falls on the Moon. 

How is a partial eclipse of the moon different to a full eclipse of the moon?

In a partial eclipse of the Moon, the Moon isn't EXAACTLY in he line between the Earth and the Sun. And so the Moon goes into the Earth's shadow, but not completely. Some part of the Moon remains illuminated.

In a total lunar eclipse the Moon passes entirely into the Earth's shadow and it becomes ALMOST completely dark.  

Eclipse of Sun

Once in a while the Moon passes directly in front of the Sun as it makes its way around Earth. It temporarily blocks out the Sun, casting a shadow on a portion of Earth thai is experiencing day. When this total eclipse of the Sun-a solar eclipse-occurs, the part of the Earth affected becomes dark and cold until the Moon passes by. Surrounding areas experience a partial eclipse, where just part of the Sun is temporarily covered by the Moon.

The moon passes in front of the sun and this causes a shadow to be cast on the earths surface. When the sun is completely covered by the moon this is called a total eclipse.