The European Space Agency's Hera spacecraft rocketed away on a two-year journey to the small, harmless asteroid rammed by NASA two years ago in a dress rehearsal for the day a killer space rock threatens Earth.

Dinosaurs certainly didn’t benefit from the Chicxulub asteroid impact, but that was a wholly different story for the ancestors of today’s ants. In fact, the climatic upheaval that rocked Earth 66 million years ago may be the major reason some of the insect species learned to farm millions of years before humans even evolved.

The Nadir crater is the impact site of the second asteroid, liquifying the rock and launching a tsunami into the Atlantic ocean.

Scientists have discovered new evidence that it wasn't just one asteroid that wiped out the dinosaurs 66 million years ago. There were two of them. It has