Around 66 million years ago, an asteroid bigger than Mount Everest smashed into Earth, killing off three quarters of all life on the planet -- including the dinosaurs.

But exactly how the impact of the asteroid Chicxulub caused all those animals to go extinct has remained a matter of debate.

However research published Monday claims that the impact winter was caused by dust kicked up by the asteroid.

Fine dust would have stayed in the atmosphere for 15 years, dropping global temperatures by up to 15 degrees Celsius, researchers said in a study in the journal Nature Geoscience.

Back in 1980, father-and-son scientists Luis and Walter Alvarez first proposed that the dinosaurs were killed off by an asteroid strike that shrouded the world in dust.

Their claim was initially met with some scepticism -- until a decade later when the massive crater of Chicxulub was found in what is now the Yucatan Peninsula on the Gulf of Mexico.

Now, scientists largely agree that Chicxulub was to blame.

An international team of researchers was able to measure dust particles thought to be from right after the asteroid struck.

The particles were found at the Tanis fossil site in the US state of North Dakota.

Though 3,000 kilometres away from the crater, the site has preserved a number of remarkable finds believed to be dated from directly after the asteroid impact in an ancient lake.

The dust particles were around 0.8 to 8.0  micrometres -- just the right size to stick around in the atmosphere for up to 15 years, the researchers said.

The dust particles "totally shut down photosynthesis" in plants for at least a year, causing a "catastrophic collapse" of life, one researcher said.