This striking scanning electron microscope image offers an intimate view of a test glass surface, part of a project to enhance the lifespan of atomic clocks in navigation satellites. The plasma-etched features, each less than 10 micrometres across, are crucial for the operation of these highly accurate clocks. They function by inducing switches between an atom’s energy states using light, laser, or maser energy (a device that produces and amplifies electromagnetic waves), leading to the emission of a stable microwave signal at a specific frequency. This microscopic image, part of an ESA project with Safran, displays conical patterns from etching and plasma effects, aiming to enhance space atomic clock reliability. The accuracy of navigation satellites hinge on precise timekeeping, as positions are determined by multiplying signal travel times by the speed of light.