Distant space collision meant doom for dinosaurs

That catastrophe eliminated the dinosaurs, which had flourished for about 165 million years, and many other life forms, and paved the way for mammals to dominate the Earth and the eventual rise of humankind, many scientists believe.

The impact is thought to have triggered a worldwide environmental cataclysm, expelling vast quantities of rock and dust into the sky, unleashing giant tsunamis, sparking global wildfires and leaving Earth shrouded in darkness for years.