Scientists believe a massive asteroid that hit the Earth about 66 million years ago completely wiped out Dinosaurs from the planet. The sun concealed itself behind a huge smoke cloud, changing days into nights and causing temperatures to drop abnormally. If that was not enough, a series of earthquakes, volcanic eruptions and giant tsunamis created conditions similar to hell on Earth. According to scientists, this was the fifth mass extinction of life on this planet or the Cretaceous-Paleogene (K-Pg) extinction event.

Asteroid impact pushed the Earth into 18 months of complete darkness

Researchers from the National Center for Atmospheric Research (NCAR) have now carried out a new study to model how soot from global wildfires after the asteroid impact would have affected the climate on Earth. The results of the survey suggest that the asteroid impact would have pushed the Earth into 18 months of complete darkness.

Charles Bardeen, the lead researcher of the study, says their research investigates what happened on Earth after the initial effects of the asteroid impact—such as earthquakes, tsunamis, and volcanic eruptions—were over. Some latest studies estimate that about 15 million tons of fine soot were generated on the planet following asteroid strike, and this huge amount of soot was carried around the world by winds.

The NCAR researchers started with these soot estimates in their simulation study. The results suggested that that much of soot in the upper atmosphere would have created a thick blanket over this planet, thus hiding the sun and blocking almost all of the sunlight. In such conditions, the days would have been as dark as a moonlit night.

Over time, the soot started to clear, and sunlight returned to somewhat normal level, but only after consuming 18 precious months.

Researchers also ran tests different amounts of soot to see how that would have affected the climate. Using a conservative soot level of 5 million tons revealed that photosynthesis would still have got disturbed for about 12 months, thus damaging the food web badly.

Level of sunlight increased quickly once the soot started to settle

Surprisingly, the results also suggest that once the soot began to sink, the level of sunlight increased relatively rapidly. The high atmospheric air cooled, causing water vapor to condense into ice and washing more soot back to the ground. In a matter of months, all the dust from the atmosphere was cleared.

While the results of this study allow researchers to understand the extended effects of an asteroid impact, the team doesn’t claim their simulation results to be perfect. For example, the geology and atmosphere during Cretaceous period was different from present-day conditions. Moreover, the model they used was not created to account for a curveball as big as an asteroid impact, and therefore the model was adjusted to allow it to handle some impacts of the event.

However, these results could help scientists in investigating the impact of a nuclear war on Earth’s climate.

The detailed findings of the study have been published in the journal Proceedings of the National Academy of Sciences.