At the heart of planets, extreme states are to be found: temperatures of thousands of degrees, pressures a million times greater than atmospheric pressure. They can therefore only be explored directly to a limited extent -- which is why the expert community is trying to use sophisticated experiments to recreate equivalent extreme conditions. Researchers have adapted an established measurement method to these extreme conditions and tested it successfully: Using the light flashes of the world's strongest X-ray laser the team managed to take a closer look at the important element, carbon, along with its chemical properties.