Curium

Curium is a hard, silvery, intensely radioactive metal. Glenn Seaborg, Ralph James and Albert Ghiorso created it in 1944 by bombarding plutonium with alpha particles in a cyclotron at Berkeley, then identified it in Chicago. It was named after Marie and Pierre Curie, pioneers of radioactivity, echoing gadolinium above it, which honors a chemist too.

Curium is made in nuclear reactors in small amounts. Curium-244 gives off so much energy that samples glow and warm themselves. Its alpha particles are used in instruments on Mars rovers: they strike rock and soil, and the response reveals which elements are there. Curium also serves as a target for making heavier elements, such as livermorium.