It is known that the fall of an asteroid on the coast of modern Mexico 66 million years ago caused the extinction of three quarters of the living world, including the dinosaurs. But the exact nature of the phenomenon caused by the Chicxulub asteroid remained a matter of debate.

According to the latest theories, sulfur released during the impact, or soot released during colossal fires, blocked sunlight and plunged the world into a long winter, AFP reported.

A study published on Monday gave new life to an earlier theory: Dust kicked up by an asteroid had blacked out the sky for a long time.

Fine silicon dust, crushed sand, would remain in the atmosphere for 15 years. According to a study published in Nature Geoscience, the lack of light would cause the average temperature to drop by up to 15 degrees Celsius.

In the 1980s, a father and son team, Luis and Walter Alvarez, suggested that the dinosaurs died out after an asteroid impact changed the climate and blanketed the Earth in dust.

This theory was called into question until the discovery, decades later, of the huge Chicxulub crater on the present-day Yucatan Peninsula in Mexico.

The theory that sulphur, not dust, could have changed the climate gained support because it was thought that the dust was not of a size to “stay in the atmosphere”, study co-author Ozgur Karatekin told AFP. Royal Observatory in Belgium.

An international team was able to identify dust particles from an asteroid impact found at the Tanis Fossil Site in North Dakota, USA. They have sizes from 0.8 to 8 micrometers.

By feeding their data into climate models similar to those used today, the researchers determined that this dust played a much larger role than previously thought.

Modeling showed that three quarters of the total amount of matter emitted into the atmosphere was dust, 24% – sulfur and only 1% – soot.

According to Karatekin, the dust particles “completely prevented photosynthesis” in plants for at least a year, leading to a “catastrophic collapse” of life.

• Follow our Facebook page, HotNews Science, to be able to receive live information and curiosities from the world of science in real time!