These images taken by NASA's Hubble Space Telescope show nine compact, ultradense galaxies as they appeared 11 billion years ago. The galaxies are only 5,000 light-years across and yet are 200 billion times more massive than the Sun. Credit: NASA, ESA, P. van Dokkum (Yale University), M. Franx (University of Leiden), and G. Illingworth (University of California, Santa Cruz and Lick Observatory)
