While the mass extinction of the dinosaurs is not a new fact to science — the giant asteroid responsible for their demise was apparently much worse than scientists originally thought.

New research shows the asteroid that hit earth 66 million years ago was 12 kilometers wide and carved a hole into the earth measuring 100km across and 30km deep. The bowl subsequently collapsed, leaving a crater more than 200km across with a shallower depth. This event threw more than 300 billion tonnes of sulphur into the atmosphere which severely lowered temperatures on Earth, a condition that lasted many years.

The crater today is located in the Gulf of Mexico, buried under sediment mostly offshore. This new research was attained during a 2016 project to drill into what remains of the crater. The co-lead investigator, a UK professor and geophysicist Joanna Morgan, worked with her team to uncover rock samples that allowed them to recreate the asteroid’s impact. Their research revealed that the asteroid struck Earth at approximately 60 degrees. It was estimated to have been moving about 18km/s.

Image: Tadek Kurpaski, Wikimedia Commons

The effect of the impact caused about 325 gigatonnes of sulphur and around 425 gigatonnes of carbon dioxide to be released into the atmosphere. The massive amount of sulphur in the atmosphere resulted in the drastic sub-zero temperatures that would have occurred immediately and lasted for years on end.

“We now know, for example, the direction and angle of impact, so we know which rocks were hit. And that allows us to calibrate the generation of gases much better,” Morgan explained to BBC News.

Dinosaurs that survived the initial impact likely lived in darkness, eventually freezing to death.