July 16, 2020 marked the 75th anniversary of the world’s first detonation of an atomic bomb in New Mexico, USA by a group of scientists working for the US government during World War 2, altering the course of warfare and human history forever.
The Trinity nuclear test resulted in the nuclear bombs tragically deployed above the Japanese cities of Hiroshima and Nagasaki to end the war, which have left a radioactive signature in the rocks.
Associate Professor Alice Gorman, Space Archaeologist at Flinders University aka Dr Space Junk, says the Trinity Test created the first example of nuclear glass where the heat of the detonation fused sand, often called Trinitite, which is also scattered around the sands of Maralinga, Australia’s nuclear test facility in the 1950’s.
“Nuclear explosions leave radioactive fallout, and dangerous high-level nuclear waste has to be carefully stored in geologically stable regions. Archaeologists typically investigate the deep past and the materials that survive into the present where we can study them,” says Associate Professor Gorman.
“Some archaeologists have looked at how you mark a nuclear waste site with materials that last as long as the half-life of radioactive materials. Plutonium 239, which was used in the Trinity test, has a half-life of 24,000 years, meaning that after this time, only half of it will have decayed into a safe, non-radioactive element.”
— Alice Gorman (@drspacejunk) July 16, 2020
The world 24,000 years ago was in the height of an Ice Age and archaeologists have found the oldest permanently occupied village, Dolni Vestonice in the Czech Republic, in that period.
In Australia, Aboriginal people were using boats on the inland Lake Mungo, now an arid region, but back then full of water. Who knows how human culture will have changed 24, 000 years from now – and will it be possible to communicate the message of ‘danger’ around nuclear sites to people of the future?
Dr Gorman says the nuclear signature of the Anthropocene era even extends into outer space.
“Plutonium is used to fuel deep space probes like Voyager 1 and 2, now outside the solar system in interstellar space, and the Viking 1 and 2 landers on Mars. This was Plutonium 238, however, which has a half-life of only 88 years.”
“At the moment, nuclear weapons in space are forbidden by the United Nations Outer Space Treaty of 1967. The 75th anniversary of the Trinity test is a good opportunity to reflect on how nuclear weapons have changed our world, and to make sure that they do not become part of our future.”