W rong time, wrong place. This week, the BBC documentary ‘The Day The Dinosaurs Died’ revealed that the extinction of dinosaurs 66 million years ago can be blamed on the most untimely asteroid possible.
Rocks recovered by researchers from the impact crater 1,300 metres under the Gulf of Mexico show if the 15-kilometre-wide asteroid had struck just a few seconds earlier or later, and therefore in a different location, the outcome might have been very different.
"It wasn’t the size of the asteroid, the scale of the blast, or even its global reach that made dinosaurs extinct," said co-presenter and scientist Ben Garrod. “It was where the impact happened.”
Huge quantities of sulphur were released from the sedimentary gypsum of the seabed because the asteroid hit shallow coastal waters. These particles reached the atmosphere, blanketing the skies in ashy darkness and triggering the ice age because sulphate particles reflect sunlight.
By contrast, if the asteroid had plunged into the nearby Atlantic or Pacific oceans, the depth of the water would likely have prevented so much vaporised rock from being released. “The cloud would have been less dense and sunlight could still have reached the planet’s surface, meaning what happened next might have been avoided,” said Dr. Garrod.
Dr. Garrod visited the research site, a drill rig stationed 30 kilometres off Mexico’s Yucatan Peninsula where a team led by Professors Jo Morgan and Sean Gulick is studying the alteration of the rocks after the collision. By doing so, they hope to better understand what happened and what the consequences were for the environment.
During the long global winter, sea temperatures drastically dropped, photosynthesis stopped and massive hurricanes and tsunamis swept the planet. All of these events played a major role in the mass extinction.
"In this cold, dark world, food ran out of the oceans within a week and shortly after on land,” Dr. Garrod said. “With nothing to eat anywhere on the planet, the mighty dinosaurs stood little chance of survival."
Another sobering thought: a few seconds later and humans would never have existed. Carpe diem.