What fell that night was not ordinary rock. Millbillillie is a eucrite, a basaltic stone blasted off the surface of 4 Vesta, one of the largest bodies in the asteroid belt between Mars and Jupiter. Eucrites belong to a family of meteorites known by the acronym HED, and they carry the chemistry of ancient lava that once flowed across a small world half a Solar System away. To hold a piece of Millbillillie is to hold a fragment of a planet that never finished forming. The journey from Vesta to the Western Australian desert took millions of years and ended in a four-second streak of light over two men and a fence.

The first pieces were not collected until 1970, a full decade after the fall. Over the years that followed, prospectors, station workers, and Aboriginal people walking the country picked up stone after stone, until more than 330 kilograms had been gathered from the plain. The largest single mass weighed around 20 kilograms. The Western Australian Museum holds that one along with a smaller 565-gram stone, but most of Millbillillie scattered into private hands and collections around the world. It remains the only meteorite of its kind ever recovered weighing more than 100 kilograms, which has made it one of the most studied and most traded eucrites on Earth.

Hold a fresh Millbillillie specimen and the first thing you notice is the crust. As the stone tore through the atmosphere, its outer skin melted into a glossy black glaze called fusion crust, sometimes rippled with flow lines where molten rock streamed backward against the wind of entry. Then the desert went to work. The iron-rich red dirt around Wiluna stained that black glass with rusty smears, so that many recovered stones wear both signatures at once: the deep space behind them and the outback that caught them. Collectors prize the contrast. Few meteorites so clearly show where they have been.

The country around Wiluna belongs to Aboriginal people whose connection to it stretches back tens of thousands of years, far longer than any pastoral lease or museum catalogue. They were among those who found the fallen stones, walking ground their ancestors had read for generations. Across Aboriginal Australia, falling fireballs and the rocks they leave behind appear in oral traditions that long predate Western science, accounts of fire from the sky woven into the law of place. Millbillillie sits at that meeting point. A piece of a vanished world, landing on some of the oldest continuously inhabited land on the planet, watched by people who already knew the sky could fall.