In 1945, the US army detonated the first nuclear test bomb at a site in New Mexico, releasing shards of radioactive glass onto the ground in the process.
Researchers have now found an unexpected use for the glass – they are using it to understand how the moon formed 4.5 billion years ago.
Minerals in the glass show surprisingly similar properties to lunar rocks, and suggest that when the moon formed, it contained very little water.
The findings provide new evidence to support the ‘giant impact theory’ of the moon’s formation.
Researchers from the Scripps Institution of Oceanography at the University of California, San Diego, examined the chemical composition of zinc and other volatile elements in glass formed under the extreme temperatures from the 1945 plutonium bomb explosion.
Test samples of the green-coloured glass, known as trinite, were collected between 10 and 250 metres from ground zero at the Trinity test site in New Mexico.
The glass closest to the detonation site was found to have very little volatile elements, such as zinc, compared with samples collected further away.
And the zinc that was present was enriched with less-reactive isotopes, which are forms of these elements with different atomic mass, but the same chemical properties.
This suggests that volatile elements were ‘dried out’ close to the explosion.