Earth has 1 in 2,700 chance this asteroid will cause its annihilation

By Dean Murray

An asteroid with a 1 in 2,700 chance of hitting us could cause a catastrophic winter.

Researchers have modeled the potential consequences of medium-sized space rock Bennu striking Earth.

The study, published in Science Advances, explores how such an event could disrupt global climate and ecosystems.

Asteroid Bennu has a diameter of about 500m, and, according to recent studies, could collide with Earth in September 2182.

"This is similar to the probability of flipping a coin 11 times in a row with the same outcome," said the IBS Center for Climate Physics (ICCP) at Pusan National University in South Korea, who carried out the study.

Using the Aleph supercomputer, the team simulated scenarios where 100–400 million tons of dust are injected into the atmosphere following a collision.

Results show that this "impact winter" could cause global surface temperatures to drop by up to 4°C, rainfall to decrease by 15%, and ozone levels to deplete by 32%.

These changes would lead to a 20–30% reduction in photosynthesis on land and in oceans, severely threatening food security worldwide.

“The abrupt impact winter would provide unfavorable climate conditions for plants to grow, leading to an initial 20–30% reduction of photosynthesis in terrestrial and marine ecosystems. This would likely cause massive disruptions in global food security,” says Dr. Lan Dai, a postdoctoral research fellow at the ICCP and lead author of the study.

The research revealed that marine ecosystems may show resilience, with plankton populations recovered within six months due to iron-enriched dust-promoting algae blooms. This could partially offset food shortages caused by reduced land-based productivity.

“On average, medium-sized asteroids collide with Earth about every 100–200 thousand years. This means that our early human ancestors may have experienced some of these planet-shifting events before with potential impacts on human evolution and even our own genetic makeup,” says Prof. Timmermann, Director of the ICCP and co-author of the study.