Our Galaxy?

1. What is the Big Bang theory?
The Big Bang theorysuggests that theuniverse as we know it today was createdafter a huge explosionor ‘bang’. GeorgesLemaitre proposed the theory of the Big Bang in 1927, andin 1929 Edwin Hubbleexpanded on his work.

2.Which is the largest galaxy?
Scientists do not know exactly. The largestgalaxies we know of aregiant elliptical (oval)galaxies located in the middle of a wholegroup of galaxies. One of the largest is in the central galaxy in the cluster Abell 2029.

3. How big is the Milky Way?
The Milky Way is huge.It takes the Sun about250 million yearsto orbit once aroundthe centre of theMilky Way.

4. What is MessierObject 31?
The AndromedaGalaxy is also known as Messier Object 31,or M 31. This galaxy is more than twice thesize of Milky Way. Butit is still not the largestgalaxy we know of.

5. Q How was the universe formed?
A The universe was born more than 15 billion years ago. It is believed that theuniverse began as a small ball of fire. Thisfireball grew larger and larger until one day it exploded, to form the universe that we know