This is an artist's impression of how the very early Universe (less than 1 thousand million years old) might have looked when it went through a voracious onset of star formation, converting primordial hydrogen into myriad stars at an unprecedented rate. The sky then would have looked very different from the sea of quiescent galaxies around us today. The sky is ablaze with primeval starburst galaxies. Giant elliptical and spiral galaxies have yet to form. Within the starburst galaxies, bright knots of hot blue stars come and go like bursting fireworks shells. Regions of new starbirth glow intensely red under a torrent of ultraviolet radiation. The most massive stars self-detonate as supernovas, exploding across the sky like firecrackers. A foreground starburst galaxy in the bottom right corner is sculpted with hot bubbles from supernova explosions and torrential stellar winds. There is very little dust in these galaxies since heavier elements have not yet been made through nucleosynthesis in stars. Astronomers think that the first stars in the Universe appeared in an abrupt eruption of star formation, rather than at a gradual pace.