GALAXY

Geography - Galaxy : 

• A Galaxy is a vast system of billions of stars, which also contains a large number of gas clouds (mainly of hydrogen gas) and dust, isolated in space from similar systems.


• There are about 100 billion galaxies (10¹¹ Galaxies) in the Universe, and each galaxy has, on an average, 100 billion stars (10¹¹ Stars). So , the total number of stars in the Universe is 10²² stars.


• The Milky Way Galaxy is the home of the Earth and our Solar System. It is spiral in shape.


• Milky Way Galaxy was formed 5 billion years after the Big Bang.


• Latest Known Galaxy is the Dwarf Galaxy.


• According to the modern thought, Universe can be classified into two parts namely  - (a) Atmosphere and (b) Space.


• Origin of the Universe is explained by the Big Bang Theory, formulated and proposed by the Belgian astronomer and cosmologist Georges Lemaitre.


• Andromeda is our nearest galaxy.