Scientists may finally have an answer to the question of why fewer stars than expected form out of interstellar material. So far, the best simulations have predicted that nearly all the matter in vast clouds of interstellar gases would eventually cool and become stars. However, only a small percentage actually does, so an international team led by CalTech has tried to create a more accurate model. They turned to a machine tailor-made for such simulations: the NSF-funded Stampede supercomputer. It turns out that star formation isn't just a local phenomenon; it's also affected by supernova explosions, radiation, stellar gases and even starlight.