Artwork of tyrannosaurs fleeing a hail of impact ejecta. Some 65 million years ago, the impact of an asteroid or comet with the Earth provoked one of prehistory's greatest mass-extinctions, when it wiped out the dinosaurs and many other species. The impact occurred in a shallow sea, off the coast of what is now Mexico, caving out a magma-filled wound some 180 kilometres across. Ejecta was thrown high into the atmosphere. The dust remained there for years, blocking out the Sun's life-giving rays. The heavier ejecta fell to earth in a torrent of molten rocks, hundreds of kilometres from ground zero. Here, tyrannosaurus rex dinosaurs living in North America are seen fleeing the onslaught, which has already set fire to the forest behind them.