Abstract The Barbados dust collections, using the mesh technique, have shown that the metal fragments and black magnetic spherules, reported earlier as extra-terrestrial, are contaminants due to handling. Coupled with observations on meshes flown in the stratosphere, it would seem that no 100 μ sized dust from outer space exists in the atmosphere. The deep-sea cosmic spherules are most likely the ablation products of meteorites, and are not continuously arriving from the zodiacal cloud. Cosmic spherules, found down deep-sea cores ought then to reflect the numbers and types of meteorites arriving on Earth in times past. The zodiacal cloud could possibly be 100 μ sized fragments of mainly an asphalty composition which burns to tarry smoke in the upper air.