BIRTH OF STARS AND GALAXIES

As time moved forward, the pull of gravity exerted its influence on the early universe. It amplified slight irregularities in the density of the primordial gas. Even as the universe as a whole continued to expand, pockets of gas became more and more dense. Stars ignited within these pockets. Groups of stars then became the earliest galaxies. Modern telescopes can detect these primordial galaxies as they appeared when the universe was only one billion years old, just 7 percent of its present age