Mankind has been broadcasting radio waves into deep space for about a hundred years now. That means there is an ever-expanding bubble announcing Humanity’s presence to anyone listening in the Milky Way. This bubble is approximately 200 light years across.
The first AM broadcast was on Christmas Eve, 1906 and Hitler’s broadcasting of the 1936 Olympics is regarded as the first signal powerful enough to be carried into space.
When compared to the vast size of the Milky Way, our presence here on Earth seems insignificant. Even our space-bound messages — which are traveling at the speed of light — are dwarfed by the galaxy’s immensity. The image illustrates our “bubble” of existence, which spans 200 light years in all directions. A very small blip in our galaxy.