On a dark night, with no moon and far from large cities, we can perceive a milky belt among the stars in the sky : the Milky Way. You just need some binoculars to discover that it is formed of innumerable stars. ¿What does this strang accumulation of stars mean? For centuries this question could not be answered. At the beginning of the 20th century an ingenious astronomer called Shapley, suggested that the Universe had the shape of a disc. So, the Milky Way would be seen as a result of looking at the disc in profile. Everything changed when Hubble showed that the Cosmos was full of many Universe-islands like ours, which nowadays we know as galaxies. You can manipulate our galaxy in the following visual to see its characterstics. Galaxy similar to the Milky Way