The Earth, also known as the blue planet, is the third planet that orbits the Sun. The latter is one of the billions of stars that form our galaxy: the Milky Way. The Milky Way is a spiral galaxy, for which we can identify two principal zones. One of them is the “bulge”, the place where the oldest stars are found, which orbit near the supermassive black hole from the centre of our galaxy: Sagittarius A* (the asterisk forms part of the name). The other zone is constituted by the disk, which is full of light elements, and it is the perfect place for the formation of new stars. It is in this last zone that resides the solar system. In particular, the Sun is found inside one of the spiral arms of the Milky Way, the Orion arm.
Beyond our galaxy, we find the Local Group, a group of galaxies formed by the Milky Way and about 40 galaxies more. In this group, our galaxy is part of the biggest three, together with Andromeda and the galaxy of the Triangle. The other ones are mainly galaxies of small size that are called satellite galaxies, as they orbit around the biggest ones.
At even larger scales, we are part of the Virgo supercluster, formed by hundreds of thousands of galaxies. Superclusters are enormous concentrations of galaxies. It is thought that in the universe exist millions of superclusters.
We still can identify an even bigger structure in the universe of which we are part of: the Laniakea supercluster. All this structure of galaxies seems to be directed to an even more massive place: the called “Great Attractor”.
At this point, we could think that we will always find a bigger and bigger structure we belong to. However, from such big scales as the last ones, the universe seems the same in all directions. It has a uniform aspect, with all matter being well distributed in any direction we look. In these conditions, it is impossible to distinguish one part of the universe from another, which prevents us from identifying our position on larger scales.