Far below you lies a sphere of solid iron and nickel about as wide as the broadest part of Texas: the Earth’s inner core. The metal at the inner core is under pressure about 360 million times higher than we experience in our everyday lives and temperatures approximately as hot as the Sun’s surface.

Earth’s planetary core is thankfully intact. But in space, similar cores can collide with other objects, causing the crystalline materials of the core to deform rapidly. Some asteroids in our solar system are massive iron objects that scientists suspect are the remnants of planetary cores after catastrophic impacts.

Measuring what happens during the collision of celestial bodies or at the Earth’s core is obviously not very practical. As such, much of our understanding of planetary cores is based on experimental studies of metals at less extreme temperatures and pressures. But researchers at the Department of Energy’s SLAC National Accelerator Laboratory have now observed for the first time how iron’s atomic structure deforms to accommodate the stress from the pressures and temperatures that occur just outside of the inner core.