A meteor the size of Mount Everest hit the Earth 66 million years ago between June and July with a force of 100 teratonnes TNT equivalent. The gaseous rock which would have been launched into the atmosphere then cooled, turned to glass, and rained down on Earth. Rather than shred the dinosaurs the glass incinerated as it fell to the surface and this heated the air to a temperature similar to that of a pizza oven. This subsequently killed the dinosaurs.