The biggest atomic blast in Australia happened 70 years ago – mysteries about its impact linger

A warning sign at one of Western Australia's Montebello islands. Liz Tynan, CC BY One winter’s day in June 1956, Britain detonated the largest weapon ever exploded in Australia. The test, code-named Mosaic G2, was conducted at Western Australia’s remote Montebello Islands, site of the first British atomic test in 1952, over 100 kilometres off the Pilbara coast. G2 was at least four times the size of the bomb that wiped out the Japanese city of Hiroshima in 1945 and perhaps six times as big. An…