THE YELLOW HILLS OF BENZENE: An image impossible to capture a few years ago, these perfect hexagons of benzene (yellow) lying across a palladium metal surface (purple) were taken at minus-300 degrees Fahrenheit by a scanning tunneling microscope. Never quite touching the surface, the tip of the microscope images the electron density cloud above the atoms and molecules. Working with physics professor Shirley Chiang, postdoctoral researchers Chris Pearson and Geoff Anderson are systematically looking at the chemistry of aromatic molecules, such as benzene, for potential use in petroleum refinement reactions.