The Hiroshima bomb site shortly after the attack (Credits: Getty Images)

The atomic bomb dropped on Hiroshima created a previously unknown material,scientists have discovered.

Researchers found the metal alloy hidden inside tiny grains of fallout left behind by the 1945 blast.

They believe it formed in the nuclear fireball itself,where temperatures of more than 7,000C instantly vaporised buildings,steel,glass and soil before everything cooled again in a matter of moments.

Such extreme conditions produced an unusual substance unlike anything scientists have ever recorded.

The newly identified metal alloy is believed to have formed inside the Hiroshima nuclear fireball (Picture: Science Advances/Cover Media)

The microscopic fragment was discovered inside a glassy particle known as a ‘hiroshimaite’,recovered from beach sands in Hiroshima Bay over 80 years after the attack.

Scientists say the alloy is made from a mixture of iron,chromium,nickel,manganese,molybdenum,silicon and aluminium – ingredients commonly found in stainless steel.

But instead of forming the way those metals normally would,the atoms became locked into a completely new arrangement as the fireball cooled at incredible speed.

Researchers say the discovery shows that nuclear explosions can create entirely new materials that simply cannot form under normal conditions on Earth.

The hiroshimaite sample up close (Picture: Science Advances/Cover Media)

For the study,scientists from the University of Florence analysed 34 tiny glassy particles collected from Hiroshima Bay.

Using powerful microscopes and X-ray analysis,they searched the debris for unusual materials created during the explosion.

One metallic grain,measuring just a few thousandths of a millimetre across,immediately caught their attention.

Although its chemical ingredients looked familiar,its internal structure matched nothing previously known.

The 81st anniversary of Hiroshima

Hiroshima in the aftermath of the atomic bomb in August 1945 which killed tens of thousands of people (Picture: Getty Images)The atomic bomb dropped on Hiroshima,codenamed ‘Little Boy’,was the first nuclear weapon ever used in war.It was released 81 years ago,at 8.15am on August 6,1945,and detonated around 1,900ft above the city to maximise the destruction below.The blast unleashed the equivalent of around 15,000 tons of TNT,and an estimated 60,000 to 80,000 people died instantly.By the end of 1945,the death toll had risen to around 140,000 as thousands more succumbed to burns,injuries and radiation sickness.The few remaining survivors of the blasts in Japan are now entering the twilight of their lives and telling their testimonies to ensure the horrors which they witnessed never repeat themselves.The Hiroshima Peace Memorial as it stands today. (Credits: Getty Images)Today,the site the bomb struck,established as the Hiroshima Peace Memorial Park and designated as a UNESCO World Heritage site in 1996,remains as a way to mark the city’s past.As decades have passed since the attack,residents and visitors can visit the city without fear of being poisoned by any nuclear radiation.After comparing it with thousands of existing materials,the team concluded that it was a new alloy.Writing in the journal Science Advances,they said: ‘We report the discovery of a previously unknown multicomponent alloy recovered from beach sands of Hiroshima Bay,formed during the August 6,1945 atomic airburst.’Scientists found the alloy’s atomic structure did not match any previously known material (Picture: Science Advances/Cover Media)The team says the findings raise the possibility that other undiscovered materials are still hidden among microscopic debris left behind by the bombing.Studying how these materials formed could also help scientists better understand how matter behaves under the most extreme temperatures and pressures.