Galaxy is a group of stars, large dark matter and dust bounded together by the gravity. The Milky Way is a bar-shaped spiral galaxy whose diameter is 100,000-120,000 light years. It contains 200-400 billion stars. It appears like a band of light from the earth at night time.
There are three major components of Milky Way-the Halo, the Nuclear Bulge and the Galactic Centre, which contains stars. In ancient times, it was called as ‘Milky Circle’. In 1610, Galileo found that the light appearance of the Milky Way is due to billions of stars. The name originates from the Greek word ‘galaxias’ which means milky. Because of the faint white appearance in night time sky it looks like spilled milk. Due to this reason, the name of this galaxy comes to be known as Milky Way.
