In a compelling revelation, recent research sheds light on an unexpected connection between the debris of the Hiroshima atomic bombing and the earliest condensates of our solar system. Published in Earth and Planetary Science Letters, the study delves into the formation process of Hiroshima glasses, a unique fallout residue discovered in Hiroshima Bay.
Led by Nathan Asset from Université Paris Cité, France, the research team scrutinized the chemical and isotopic compositions of Hiroshima glasses to unravel the mysteries of their origin. Their findings suggest that these glasses were formed through rapid condensation, occurring within a mere 1.5 to 5.5 seconds amid the intense nuclear fireball, reminiscent of the process behind the creation of calcium-aluminum-rich inclusions (CAIs) found in primitive meteorites.
Analyzing 94 specimens of fallout debris, the team identified four distinct types of glasses: melilitic, anorthositic, soda-lime, and silica. Each type offers crucial insights into the conditions and materials involved in their formation. While the silica glass’s origin remains ambiguous, the soda-lime glasses bear similarities to industrially produced compositions.
The researchers reconstructed the formation sequence of these glasses, revealing the staggering temperatures and pressures endured during the nuclear explosion. Within fractions of a second, materials from the cityscape, including concrete, iron, and industrial glass, were vaporized and intermixed with sand, river water, and atmospheric gases, culminating in the diverse compositions observed in the Hiroshima glasses.
Despite the challenges in estimating vaporized quantities due to varying structural resilience of buildings, the isotopic compositions of the glasses align closely with those of CAIs. This alignment provides crucial clues regarding the chronological sequence of glass formation, with melilitic glasses being the earliest to form, followed by anorthositic, soda-lime, and finally, nearly pure silica.
While disparities exist between the environmental conditions of Hiroshima glass formation and those of CAIs in the solar accretion disk, understanding the underlying processes illuminates our understanding of the solar system’s origins. By delving into the gas-solid transition dynamics, this research offers a fascinating glimpse into the interconnectedness of terrestrial events and cosmic phenomena, enriching our comprehension of the universe’s evolutionary tapestry.
