Star formation. Image 5 of 6. Computer model of a 1.2-light-year-wide interstellar gas ball 266,000 years after it began collapsing, a process that causes star formation. The ball contains 50 solar masses of gas and collapses under its own gravity. Brighter areas are denser. Interactions between the new stars (white) have led to some being flung from the centre. This model used 100,000 process- ing hours on a supercomputer at the United Kingdom Astrophysical Fluid Facility (UKAFF) at Leicester University, UK. It will increase understanding of the star formation process, and the likelihood of planetary system formation. For a sequence lasting 266,000 years, see images R590/089-094.