Lives of the Galaxies
Astronomers have a far better understanding of the life cycles of individual stars than they do of galaxies.
Although stars within the galaxy may be seen in a variety of evolutionary stages, few examples of young galaxies
are known. Because of the finite speed of light, recent observations of galaxies at large distances have permitted
us to look back in time to the early history of the Universe and trace the evolution of galaxies. The left panel
gives one example of such studies.