The Glikson structure first surfaced not in a photograph but in an aeromagnetic survey, where a strikingly circular anomaly hinted at buried violence. Most of the site is smothered by dunes; only sparse outcrops of uplifted, deformed Neoproterozoic sandstone break the surface. The telltale ring almost certainly marks where the impact shattered a buried sheet of magnetic igneous rock, a sill, snapping a once-flat layer into a circle. It is a strange way to find a crater, reading the planet's magnetism like a hidden text. The collision wrote its signature deep in the rock, and the desert, by burying everything else, accidentally preserved exactly that one legible line.

A circle in the magnetism is a clue, not a verdict. The proof came from the rocks themselves. Geologists found shatter cones, distinctive branching fractures that form only under the colossal, instantaneous pressure of an impact, alongside microscopic shock effects in the mineral grains. Nature has no slow way to make these. Tracing the deformed sandstone outward, researchers mapped the damage to about 19 kilometres across, their best estimate for the original crater's true diameter, roughly a third wider than the visible magnetic ring. The bowl has vanished. The scars it pressed into the bedrock have not, and they speak clearly enough to settle the question of origin.

Dating an eroded crater means dating the rocks around it. Nearby dolerite has been measured at 508 million years old, with an uncertainty of about 5 million years either way, placing it in the Middle Cambrian. If that same igneous rock is the source of the magnetic ring, then the impact had to come afterward, sometime in the Paleozoic, the long era when fish filled the seas and the first forests crept across the land. There is no neat figure, no single year. There is only a floor beneath which the event cannot lie, and the patient logic geologists use to read time from stone when no fresher evidence survives. The dunes that buried Glikson erased the easy answers, so the rock has to be cross-examined instead, one clue at a time.

The structure carries the name of Andrew Glikson, an Australian geologist who graduated from the University of Western Australia in 1968 and spent a career hunting impacts across the continent, eventually counting dozens of proven and possible craters. A possible impact here was first reported in 1997 and named in his honour. The tribute proved fitting in an unexpected way. A decade later, when Arthur Hickman spotted a suspicious circle north of Newman on Google Earth, it was Glikson he emailed for a second opinion, and Glikson who confirmed it as a true crater. Two scars in the Western Australian desert, one fresh and one ancient, are bound together by the same expert eye, and now by the name on a map.