Despite only having a small chance of impacting Earth, asteroid Bennu could unleash substantial global damage, rivaling effects from massive volcanic eruptions, a new study warns, CNN reports.
While significantly smaller than the asteroid that wiped out the dinosaurs, Bennu’s potential collision is far from harmless.
Astronomers estimate a 1 in 2,700 (0.037%) chance of Bennu impacting Earth in September 2182. This medium-sized space rock, measuring approximately 1,640 feet (500 meters) in diameter, contains the building blocks of life, as recently discovered by NASA’s OSIRIS-REx mission.
The study, published Wednesday in the journal Science Advances, details the modeled effects of a Bennu-type collision on Earth’s climate and ecosystems. Researchers ran simulations on the Aleph supercomputer at ICCP, focusing on scenarios involving the injection of 100 million to 400 million tons of material into the atmosphere.
The results paint a grim picture. A Bennu impact would lead to:
- Global Winter: Reduced rainfall and drastically cooler temperatures could persist for years following the impact.
- Atmospheric Disruption: Massive amounts of aerosols and gases released into the atmosphere would alter Earth’s climate chemistry.
- Tsunamis and Ozone Depletion: An ocean impact would trigger massive tsunamis and deplete the ozone layer for years.
- Temperature and Rainfall Reduction: In the worst-case scenario, with 400 million tons of dust in the atmosphere, global temperatures could plummet by as much as 7.2 degrees Fahrenheit (4 degrees Celsius), and rainfall could decrease by 15%. The ozone layer could also thin by 32%.
The study draws parallels to the effects of the Mount Toba super-eruption 74,000 years ago, one of the largest volcanic events in Earth’s history, which also caused significant global cooling.
Interestingly, the study also revealed a surprising potential consequence for marine life. While initially expected to decline, marine plankton could recover within six months and even experience an unprecedented population boom, particularly if Bennu’s composition is rich in iron.
Harvard University planetary scientist Nadja Drabon, who was not involved in the study, noted that the research aligns with existing knowledge of earlier impact events.
