Researchers from the University of Paris-Cité in France have identified substances never before seen, created during the earliest use of nuclear weapons. These materials emerged as a direct result of the first atomic bombing, the August 1945 attack on Hiroshima by the United States Army. The scientists describe the compounds as bearing similarities to materials found in space, and their work appears in the scientific journal Earth and Planetary Science Letters (EPSL).
The newly detected substances were termed Hiroshima glasses. They formed when the intense energy of a nuclear fireball vaporized surrounding materials, letting them mix with the ambient environment and then condense into glass-like phases as the plume cooled quickly in the upper atmosphere.
By retracing how these glasses formed, researchers have gained insights into the dynamics of the Hiroshima eruption. Their calculations indicate that the luminous plasma sphere rose above the city to an altitude of about 580 meters, while the peak heat of the ensuing wave reached approximately 6,287 degrees Celsius. This combination of altitude and extreme thermal input played a crucial role in shaping the condensed materials that settled on the ground and surrounding areas.
During the initial 0.5 to 2 seconds after the explosion, urban substances such as concrete, iron and aluminum alloys, glass, and soil underwent rapid vaporization. These plumes interacted with sand, river water from the Ota, and the surrounding atmosphere, producing a glassy condensate that captured a snapshot of the event in mineral form. The resulting materials serve as a tangible record of the explosion’s immediate aftermath and its interaction with the built environment.
From a broader perspective, the scientists note a remarkable parallel with the early history of the solar system. In those ancient moments, the first solid bodies formed as interstellar dust and gas were heated, vaporized, and then recondensed in the nebulae. Although the pressures, temperatures, and timescales of a nuclear detonation differ vastly from cosmic processes, the parallel in material behavior offers a unique window into how matter can transition from vapor to solid in extreme conditions. By comparing laboratory- and field-derived evidence with models of planetary formation, researchers can better understand the sequence of events that led to the emergence of our stellar neighborhood.
Historical discussions on protective shelter in the face of nuclear blasts have underscored the importance of understanding material responses to extreme energy releases. The current findings add a piece to that discourse by illustrating how rapid heating, vaporization, and subsequent cooling can create distinct mineralogical signatures. These signatures act as records of the explosion’s intensity and the environmental context in which it occurred, providing a scientific lens through which to interpret past events—even decades later—without venturing into speculation about present-day applicability.