Dinosaur-killing asteroid could have thrust Earth into two years of darkness

Tremendous amounts of soot, lofted into the air from global wildfires following a massive asteroid strike 66 million years ago, would have plunged Earth into darkness for nearly two years, according to a news release from the National Center for Atmospheric Research (NCAR). This event would have shut down photosynthesis, drastically cooled the planet and contributed to the mass extinction that marked the end of the age of dinosaurs.