For the first time, an international team has tracked at BESSY II how heavy molecules—in this case bromochloromethane—disintegrate into smaller fragments when they absorb X-ray light. Using a newly developed analytical method, they were able to visualize the ultrafast dynamics of this process. In this process, the X-ray photons trigger a "molecular catapult effect": light atomic groups are ejected first, similar to projectiles fired from a catapult, while the heavier atoms—bromine and chlorine—separate more slowly.