Title: Plutonium
Headings: Plutonium Element Facts
Plutonium Element Facts
Pu
Data Zone
A plutonium ‘button.’ Photo: Department of Energy
Discovery of Plutonium
Dr. Doug Stewart
Appearance and Characteristics
Harmful effects:
Characteristics:
Uses of Plutonium
Abundance and Isotopes
References
Cite this Page

Content: Its intrinsic heat output is approximately 0.5 watts per gram.) The Pioneer and Voyager space probes used plutonium-238 nuclear batteries as a power source. Three radioisotope heater units (each containing 2.7 grams of plutonium-238 dioxide) were used as heat sources on the Pathfinder Mars robot lander. Each radioisotope heater unit produces about one watt of heat. ( 6), (7)
Early pacemaker batteries also used tiny amounts of plutonium-238. The image on the left shows the decay of one atom of plutonium-238. This releases 5.6 million electron volts of energy. To get an idea of what this means, consider NASA’s Curiosity Mars rover, which will be powered by 4.8 kg of plutonium dioxide. During its first 87.7 year half-life, the plutonium will produce about 4800 gigajoules of energy. To generate the same energy using natural gas (mainly methane) the Mars rover would need to carry about 86 metric tons of methane and 345 metric tons of oxygen.