1. Milky way

2. THE SIZE OF THE UNIVERSE Some astronomers believe that the Universe is infinite, going on in all directions forever. Others have estimated that the Universe has expanded to the point that it’s about 150 billion light years across since the Big Bang; and it’s getting bigger every day.

3. Big Bang Theory There are many misconceptions surrounding the Big Bang theory. For example, we tend to imagine a giant explosion. Experts however say that there was no explosion; there was (and continues to be) an expansion. Rather than imagining a balloon popping and releasing its contents, imagine a balloon expanding: an infinitesimally small balloon expanding to the size of our current universe.

4. BIG BANG THEORY The expansion of our universe began with an explosion or big bang some six thousand million years ago.It all happened when all the matter was closely packed together in a limited space.