علوم بالغه الانجليزيه()Near and far universal space

زائر

Stars:

They are large gaseous bodies in space which generate heat and light.

Light year:
It is the distance covered by light in one year and equal: 9.46 × 10¹² km.

Galaxy:

It is a group of millions of stars and it is the biggest units of the universe.

Constellation:

A galaxy can be divided into small groups called "Constellations".

The most famous constellations are:

a- The ursa major (great bear)

b- Scorpion.

c- Gemini (the twin).

Astronomical unit:

It is the average distance between the sun and the earth equals 150 million kilometers (150 × 10⁶ kms.)

The most important instruments used in exploration of outer space are:

a- Telescopes.
b- Artificial satellites.
c- Space ships.

The invasion of space:

It started on fourth of October 1957.

Types of telescopes are:

a- Refracting telescope.

b - Reflecting telescope.

Galileo:

He was the first scientist who proved that sun is the centre of the universe (solar system).