The smell of fresh bread says a bakery is near. But to know if baking is happening right now, it’s the intensity of the scent — a stream of aroma from the oven — that matters, not just the smell itself. Same goes for hunting life on other planets. Before, we’d merely measure how much “living” gas was in the air — like judging the baking solely by the room’s aroma. But gases also pile up from non-living processes. The new method clocks how fast gases escape the surface, as if tracking the hot air gushing from an oven: a steady, warm flow means something’s baking inside. That’s how fresh microbial emissions get separated from ancient reservoirs. Scientists tried the idea on a model of planet TRAPPIST-1 e — a twin of early Earth. A virtual telescope captured light fingerprints of the atmosphere, and the model computed the fluxes. It nailed carbon dioxide and methane, with the methane flux pointing to living producers at 80% probability. It’s not a verdict, but a weighty clue. We’re after not just traces of life, but its breathing — right now.