The extinction of dinosaurs on Earth: scientists made a key mistake, but what does the smell of eggs have to do with it?

About 66 million years ago, a massive asteroid known as Chicxulub struck Earth, resulting in the formation of an impact crater approximately 200 kilometers wide on the Yucatán Peninsula. The subsequent events are known to have wiped out 75% of species on Earth, including the dinosaurs. But what truly triggered the mass extinction? Scientists believe they have discovered something that was previously overlooked, as reported by IFLScience.

The massive release of sulfur significantly contributed to the abrupt cooling of the planet that followed the catastrophic asteroid impact. But did events unfold as we previously thought? In a new study, researchers examined the long-held belief that the sulfur eruption, among other factors, caused a harsh, prolonged "impact winter." Now, researchers believe that earlier studies likely overestimated the amount of sulfur that was actually released.

When the enormous asteroid collided with Earth, it sent a cloud of dust, soot, and other materials into the atmosphere, creating what scientists refer to as "impact winter." Essentially, at that moment, the planet was plunged into extreme cold and darkness: plants could not photosynthesize, and animals could not thrive. In the case of the Chicxulub asteroid, its impact led to a complete reshuffling of the animal kingdom.

In this destructive dust cloud, scientists had previously singled out one particularly "guilty" factor for the extinction: sulfur. However, the exact amount of sulfur released remains a topic of debate, with estimates from scientists varying widely. The key questions that still lack answers include: Was there a lot of sulfur-rich rock at the impact site? At what speed and angle did the asteroid strike? What implications does this have for the subsequent distribution of sulfur?

In the new study, researchers utilized cores extracted from impact rocks at the Chicxulub site in Mexico. The authors of the study note that their work is the first empirical attempt to quantify how much sulfur was actually released during the asteroid impact.

According to co-author, chemist Katerina Rodyushkina, they and their colleagues focused not on the impact event itself but on its aftermath. Initially, they analyzed the sulfur signature of rocks in the crater area, which were the source of sulfate aerosols ejected into the atmosphere.

These aerosols spread globally and were eventually returned to the planet's surface from the atmosphere over the course of months, or possibly years, following the impact. Sulfur deposited around the K-Pg boundary in sedimentary profiles worldwide. In the course of the study, scientists employed the relevant isotopic composition changes of sulfur to distinguish that which was associated with the impact from natural sources. Consequently, the total amount of sulfur released was calculated using mass balance.

As a result, the researchers concluded that previous estimates were inflated, with some exceeding the new findings by a factor of five. The team believes that a total of 67 ± 39 billion tons of sulfur was released, suggesting that a milder impact winter followed than previously thought.

In simple terms, the temperature on the planet did decrease, but likely not as drastically, and the climate would have returned to nearly normal much sooner than assumed. The authors of the study also believe that their discovery may explain why, despite all the drama of the Earth's fourth life, some species managed to survive.