Dr. Zega applies a microscopy- and microanalysis-based approach to study the chemical and physical evolution of the early solar system and ancient stars. His current efforts are focused on the origin of refractory inclusions, presolar grains, primitive organics, interplanetary dust particles, and material retrieved from the Stardust mission. He uses ultrahigh-resolution ion- and electron-microscopy techniques, including focused-ion-beam scanning-electron microscopy and transmission electron microscopy, to determine the composition and structure of these materials at scales ranging from millimeters down to a fraction of a nanometer. Knowledge of these intimate details of planetary materials provides incomparable insights into the origin of our solar system and ancient stars.