Early star formation. Supercomputer simulation of the birth of a first generation star known as a Population III star. This simulation shows the volume of neutral stellar gas (blue is low density, orange to green is high density). The frame is 45,000 light-years across. At centre is the star (unseen) at the beginning of the simulation. Population III stars were thought to be the first stars in the universe. Calculations suggest they were brighter, hotter and several times more massive than today's most luminous stars. As Population III stars exploded into massive supernovae, known as hypernovae, they dispersed heavy elements and initiated the process that would make planets and life possible.