THE HISTORY OF THE GALAXIES

Astronomical observations now reach far enough back in time, in enough depth and detail, to reveal the history of galaxies since their forma tion. The early Universe contained a network of gas clouds that filled much of the space between the young galaxies, where stars were formin g at a high rate. Since then, intergalactic space has been swept clean , and galaxies have continued to convert the dwindling supply of gas s low into stars.