text: Hubble Approaches the Final Frontier: The Dawn of Galaxies Hubble Space Telescope -- Hubble Space Telescope -- Detailed analyses of mankind's deepest optical view of the universe, the Hubble Ultra Deep Field (HUDF), by several expert teams have at last identified what may turn out to be some of the earliest star-forming galaxies.     Astronomers are now debating whether the hottest stars in these early galaxies may have provided enough radiation to "lift a curtain" of cold, primordial hydrogen that cooled after the big bang...