History of chemistry element among the fractions that resulted. Working with the mineral pitchblende, the pair discovered a new radioactive element in 1898. They named the element polonium, after Marie's native country of Poland. On December 21, 1898, the Curies detected the presence of another radioactive material in the pitchblende. They presented this finding to the French Academy of Sciences on December 26, proposing that the new element be called radium. The Curies then went to work isolating polonium and radium from naturally occurring compounds to prove that they were new elements. In 1902, the Curies announced that they had produced a decigram
Isotopes of polonium per second as 5 grams of Ra. A few curies (1 curie equals 37 gigabecquerels) of Po emit a blue glow caused by excitation of surrounding air. A single gram of Po generates 140 watts of power. Because it emits many alpha particles, which are stopped within a very short distance in dense media and release their energy, Po has been used as a lightweight heat source to power thermoelectric cells in artificial satellites; for instance, a Po heat source was also in each of the Lunokhod rovers deployed on the surface of the Moon, to keep their internal components