Curiosity Runs on Plutonium, Not Sunlight

While other Mars rovers died when dust blocked their sun, this one just kept driving. Its secret is a lump of plutonium.

Solar rovers live and die by the sky. One thick dust storm can starve them in weeks. Curiosity ignores the weather completely.

Inside Curiosity sits a nuclear battery called an RTG, holding about 4.8 kilograms of plutonium. The plutonium is naturally warm, glowing with its own heat as it decays, and that heat becomes electricity. No moving parts, no sunlight needed. It even warms the electronics through Martian nights below minus 80 degrees Celsius. Curiosity landed in 2012 with power planned for one Martian year. More than a decade later, it is still drilling and sending data home.

The plutonium's half-life is about 88 years. The rover's parts will fail long before its power runs low. Curiosity is a nuclear robot that could outlast the engineers who built it.

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