Credit: NASA/JPL-Caltech/R. Hurt (SSC-Caltech)

This three-panel diagram shows the process of triggered star formation. In the first panel, a massive, dying star explodes or "goes supernova." In the second panel, the shock wave from this explosion passes through clouds of gas and dust (green). In the third panel, a new wave of stars is born within the cloud, induced by the shock from the supernova blast. The whole progression, from the death of one star to the birth of others, takes millions of years to complete.