Scientists discover how mitochondria import antioxidants

Many of the processes that keep us alive also put us at risk. The energy-producing chemical reactions in our cells, for example, also produce free radicals—unstable molecules that steal electrons from other molecules. When ...

Twin of NASA's Perseverance Mars rover begins terrain tests

On a recent day in November, the car-size rover rolled slowly forward, then stopped, perched on the threshold of a Martian landscape. But this rover, named OPTIMISM, wasn't on the Red Planet. And the landscape was a boulder-strewn ...