"I'm as happy as anyone that the Curiosity rover got to Mars; it's hard not to barrack for all those NASA geeks in their blue polo shirts. But before you get all apple pie about the achievement, there's something you should know: Curiosity runs on plutonium from a Soviet-era nuclear weapons plant."
This chart contains information on all of the isotopes of the elements. Very comprehensive, and a useful resource for atomic structure and nuclear chemistry units within chemistry.