Dinosaur research Starved or burned: How did the dinosaurs die?

A new study has added fuel to a long-standing scientific debate over the cause of the dinosaurs' extinction 66 million years ago. Researchers are still divided over whether the creatures perished due to prolonged starvation during a global darkness caused by asteroid debris or were instead incinerated within hours by intense heat generated by the impact. The latest findings from Purdue University suggest that the Earth could have become a planet-wide oven, with extreme temperatures capable of burning forests and killing animals in a matter of hours. The asteroid strike, which created the Chicxulub crater in present-day Mexico, was one of the most catastrophic events in Earth's history. Scientists widely agree that the object, estimated to be around 13 kilometers in diameter, struck the planet with such force that it would have covered the entire city of Zurich and parts of Lake Zurich. Its speed, approximately 20 kilometers per second, was enough to traverse the distance between Bern and Basel in less than four seconds. This immense energy triggered massive atmospheric disturbances, including the release of vast amounts of dust and gases into the atmosphere. In the aftermath of the collision, larger fragments of rock fell back to Earth quickly, while finer particles remained suspended in the air for extended periods. These fine particles blocked sunlight, plunging the planet into a prolonged period of darkness. Without sunlight, plants could not perform photosynthesis, leading to widespread die-offs and ultimately causing food shortages for herbivorous dinosaurs. Over time, this scarcity likely led to the collapse of entire ecosystems, contributing to the mass extinction event. However, some researchers argue that the immediate effects of the impact were far more devastating. As the large rock fragments re-entered the atmosphere, they generated intense heat, similar to the glow of a rocket re-entering Earth’s atmosphere. Until recently, scientists believed this heat was confined to the immediate vicinity of the impact site. But the new research challenges this view, suggesting that the heat was actually trapped beneath a layer of fine dust that formed rapidly after the initial impact. This dust layer acted like a lid on a boiling pot, preventing heat from escaping into space. As a result, the Earth became a giant furnace, with surface temperatures rising dramatically. According to the study, this heat was sufficient to ignite forests and other vegetation, potentially leading to widespread wildfires. Animals exposed to these conditions may have suffered severe burns or succumbed to the extreme heat. The evidence supporting this theory comes from geological samples found in the United States. Researchers observed that the larger rock fragments and fine dust from the era were separated rather than mixed, indicating that they fell to Earth at different times. This supports the idea that the two types of material behaved differently in the atmosphere, with heavier fragments descending quickly and lighter particles lingering longer. Despite this compelling evidence, the fire hypothesis remains controversial. Many scientists still believe that the gradual loss of plant life over several years played a key role in the extinction of the dinosaurs. They point to patterns in the survival rates of different species that align more closely with the starvation hypothesis. Nevertheless, the new findings provide a fresh perspective on the immediate consequences of the asteroid impact, adding complexity to our understanding of one of the most dramatic events in Earth's history. As further research continues, the debate over the exact causes of the dinosaur extinction will likely persist. What is clear, however, is that the asteroid impact had profound and lasting effects on the planet's biosphere, reshaping the course of evolution for millions of years.