Artist’s impression comparing a smooth stellar wind (left) with a highly fragmented stellar wind (right) of a massive star like zeta Puppis. A decade’s-worth of observations with ESA’s XMM-Newton have revealed that the wind of zeta Puppis is fragmented into hundreds of thousands of individual hot (red) and cool (blue) clumps. Studying stellar winds is vital not only to understand mass loss from the star itself and thus its expected lifetime, but also how the winds inject material and energy into the surrounding environment and influence the birth and death of other stars.