The clash of a medium -sized asteroid could create a world winter and drought

In a week in which asteroid 2024 YR4, between 40 and 90 meters in diameter, has monopolized the attention of the media due to the possibility, of 1.5%, to collide against our planet in 2032, Science Advances magazine publishes a study in which the possible effects of a much greater body are modeled.

A team led by the Climate Physics Center, from the Institute of Basic Sciences of the National University of Pusan ​​(South Korea) took the Bennu Asteroid.

That object could cause considerable damage if it collided with the earth in 2182, Although the estimated probability is 1 between 2,700 (how to launch a currency 11 times in a row with the same result).

The study considers Dust injections between 100 and 400 million tons to the atmosphere, with which simulations show drastic alterations in the weather, atmospheric chemistry and global photosynthesis in the 3 or 4 years following the impact.

The worst scenarios contemplates that up to 400 million tons of dust reach the atmosphere, in addition to aerosols, debris and ashes, which would produce solar obscure.

The result would be a global cooling of the surface of up to 4 degrees, a reduction in 15 % global average rainfall and a serious exhaustion of the ozone of around 32 %, triggering a global winter and extreme falls of net primary productivity.

An ‘impact winter’ caused by persistent dust could seriously affect global photosynthesis; Net terrestrial primary productivity could collapse up to 36% and the sea up to 25%. Regionally, these impacts could be much more pronounced.

That abrupt winter would provide unfavorable climatic conditions for plant growth, which would cause an initial reduction of 20-30% of photosynthesis in terrestrial and marine ecosystems, which would probably cause massive disorders in world food safety.

The data of the models, however, point out that the growth of the plankton showed a completely different behavior, as it was recovered in just six months and even increased to levels that were not even seen in normal climatic conditions.

Depending on the iron content of the asteroid and terrestrial material, which is expelled to the stratosphere, The regions that would otherwise be devoid of nutrients could be enriched with bioavailable iron, which in turn would trigger an unprecedented proliferation of algae.

If the asteroid produced dust especially rich in iron, diatoms (an algae type) could flourish in the Eastern Ecuadorial Pacific and the Antarctic Ocean during the following three years.

The authors point out that these results do not take into account the additional effects of soot and sulfur emissions of forest fires.

Object impacts have been produced many times in the history of the earth and The last great known asteroid was the one who created the Chicxulub crater, northwest of Mexico, and ended the dinosaurs.

That asteroid that collided with the Earth 66 million years ago had about ten kilometers in diameter, compared to 500 meters from Bennu, the one used for this simulation.

The Bennu Asteroid is, together with another called Ryugu, the only two of which spaces spaces have brought to the earth samples for its study.

NASA’s Osiris-Rex mission deposited about 120 grams of material on our planet, approximately the weight of a soap pill, from Bennu and are generating many scientific studies.

The most recent, from the end of January, indicated that remains of ancient brine discovered in the asteroid contain crucial minerals for life on Earth, in addition to compounds never before observed in samples of such an body.