On July 16, 1945 humans detonated our first nuclear weapon. Code named Trinity, the detonation released the energy equivalent to 20 kilotons of TNT and was hot enough to turn sand into glass. More than 70 years later, researchers led by James Day - at Scripps Institution of Oceanography at the University of California San Diego - are studying shards of this radioactive glass with hopes of solving a grand scientific mystery: how the Moon formed. Turns out, the temperatures and pressures at the point of detonation back in 1945 were similar to the conditions that would have occurred during a giant impact between Earth and a Mars-sized object around 4.5 billion years ago, the scientists report.