ATOMIC STEERING COMMITTEE. Even the smoothest-looking coatings are very rough on the atomic scale, with islands of atoms peppered abundantly across the microscopic landscape. Depositing copper atoms on a Cu surface, researchers (Sebastiaan van Dijken, University of Twente, the Netherlands, s.vandijken@tn.utwente.nl) have identified a largely ignored mechanism which contributes to introducing roughness in films of atoms being deposited onto surfaces. Known as steering, it arises when surface atoms, including already deposited ones, exert chemical forces on incoming atoms and cause them to veer towards the surface. This is reminiscent of how static electricity can cause some of the milk poured from a glass to drip down the sides rather than fall freely from the glass. Steering causes incoming atoms, especially those approaching the surface at grazing angles, to arrive preferentially on the top of protruding islands of atoms. Therefore, steering can make already rough surfaces even rougher. Besides providing insights into the causes of roughness, understanding this effect may help researchers to prepare arrays of surface ridges, which could serve as templates for making magnetic nanowires and other customized materials. (S. van Dijken et al., Physical Review Letters, 17 May 1999; see figure at Physics News Graphics)