One day within the last several thousand years, a rare metallic meteorite travelling over 12 000 km/hour smashed into Earth’s surface near what is today the trackless border region between Egypt, Sudan and Libya. The impact of the 1.3 m, 10-tonne chunk of iron generated a fireball and plume that would have been visible over 1000 km away, and drilled a hole 16 m deep and 45 m wide into the rocky terrain.
Since then, the crater had sat undisturbed by Earth’s geologic and climatic processes, which usually render all but the very largest terrestrial impact craters invisible. It was also, as far as is recorded, unseen by humans.
But that changed in 2008, when the crater was spotted during a Google Earth study conducted by mineralologist Vincenzo De Michele, then with the Civico Museo di Storia Naturale in Milan, Italy. He was searching for natural features, when by chance he saw the rounded impact crater on his PC screen.
De Michele contacted an astrophysicist, Dr Mario Di Martino, at the INAF (National Institute for Astrophysics) observatory in Turin, who, together with Dr Luigi Folco, of Siena’s Museo Nazionale dell’Antartide, organised an expedition to the site in February this year…
After a tiring, GPS-guided, three-day drive across the desert in 40°C heat, the team reached the crater.
They collected over 1000 kg of metallic meteorite fragments, including one 83-kg chunk thought to have split from the main meteorite body shortly before impact (it was found 200 m away from the crater). The joint team also conducted a thorough geological and topographical survey, using ground-penetrating radar to create a 3D digital terrain model. Geomagnetic and seismic surveys were also carried out.
The researchers were stunned to find that Kamil crater, named after a nearby rocky outcrop, remains pristine, and must have been created relatively recently…
“We are still determining the geochronology of the impact site, but the crater is certainly less than ten thousand years old — and potentially less than a few thousand. The impact may even have been observed by humans, and archaeological investigations at nearby ancient settlements may help fix the date,” says Dr Folco.
Google Earth rules. I’ve used it to trace El Camino Real, the original trail between Mexico City and colonial Santa Fe over four hundred years ago. I get motivated to crank it up, again – every time I bump into one of these tales.