Giant planets like Uranus and Neptune may contain much less free hydrogen than previously assumed. Researchers from the German Helmholtz-Zentrum Dresden-Rossendorf (HZDR) drove shock waves through two types of plastic to reach the same temperatures and pressures present inside such planets, and observed the behavior using ultra-strong X-ray laser pulses. Unexpectedly, one of these plastics kept its crystalline structure even at the most extreme pressures reached. Since the icy giant interiors are made up of the same components as the plastic, planetary models may need to be partially reconsidered, as reported in the journal Scientific Reports.