For the first time ever, researchers have witnessed—in real time and at the molecular-scale—hydrogen and oxygen atoms merge to form tiny, nano-sized bubbles of water.

The event occurred as part of a new Northwestern University study, during which scientists sought to understand how palladium, a rare metallic element, catalyzes the gaseous reaction to generate water. By witnessing the reaction at the nanoscale, the Northwestern team unraveled how the process occurs and even uncovered new strategies to accelerate it.

Because the reaction does not require extreme conditions, the researchers say it could be harnessed as a practical solution for rapidly generating water in arid environments, including on other planets.