Perseverance Radioisotope Thermoelectric Generator on Mars

NASA's Perseverance Mars rover looks back at its wheel tracks on March 17, 2022, the 381st Martian day, or sol, of the mission. Perseverance carries a Radioisotope Power System, visible on the left of the rover (featuring the large white fins). This power system, known as a Multi-Mission Radioisotope Thermoelectric Generator (or MMRTG), produces a dependable flow of electricity using the heat emitted from the natural radioactive decay of plutonium oxide as its "fuel."