> Drabon and her colleagues went in search of evidence of ancient major impacts in a remote area south of Kruger National Park in South Africa. There they sought out rocky outcrops containing a layer of spherules – molten droplets formed following a major meteorite impact that rained down over huge swathes of the planet. There are eight such spherule bands in this area, each preserving an ancient impact event.
> While the impact crater itself is long gone, analysis of rocks from 3.26 billion years ago tells a tale of planetary devastation. The layer of spherules from this huge impact was 15 to 20cm thick in places, compared with less than a centimetre for the famed dinosaur-killing meteorite, says Drabon.