Researchers at the US Department of Energy’s Lawrence Berkeley National Laboratory have captured the moment when atoms form a covalent bond. The team happened upon the discovery by accident: they set out to build graphene nanostructures, and used an atomic force microscope to ensure they had correctly arranged the atoms. Much to their surprise, the microscope captured some stunning images of carbon atoms and their bonds.

"We weren't thinking about making beautiful images... but to really see what was happening at the single-atom level we had to use a uniquely sensitive atomic force microscope," explains Felix Fischer, a scientist who worked on the project. "Nobody has ever taken direct, single-bond-resolved images of individual molecules, right before and immediately after a complex organic reaction." As Berkeley Lab's News Center notes, the photographs bear a "startling resemblance" to the diagrams used to teach chemistry, "except here no imagination is required."