The Milky Way is not a road, of course. It is the name of our galaxy , which consists of approximately 200-300 billion stars. The Earth came into existense after a stellar explosion in the Milky Way about 4.7 billion years ago. Scientists believe that smaller galaxies have formed larger galaxies, and that these in turn connect to form giant heaps of galaxies. The Milky Way is a galaxy in one such heap consisting of about 40 galaxies.

Our galaxy is about 100,000 light years in diameter and about 2,9 million light years from its closest neighbour, the Andromeda Galaxy.In spite of the vast space between them, galaxies do occasionally collide. Our galaxy is estimated to collide with the Andromeda Galaxy in 5 billion years or so and the collision itself may last for 100 million years.