Washington DC, US
Reuters
Asteroid Bennu, a rocky near-Earth object, poses a potential threat to Earth, despite its average distance of about 299,000 kilometers during its closest approach every six years. Scientists estimate a minuscule but notable one-in-2,700 chance of a collision with our planet in September 2182. However, the consequences of such an event could be catastrophic, as detailed in a recent study using computer simulations.
Asteroid Bennu: A Closer Look
Bennu is categorized as a medium-sized asteroid, with a diameter of roughly 500 meters. It is classified as a “rubble pile” asteroid, meaning it is a loose aggregate of rocks rather than a solid object. This classification adds interest to Bennu because it provides a window into the early formation of our solar system, approximately 4.5 billion years ago.
This mosaic image of asteroid Bennu, composed of 12 PolyCam images collected on December 2, 2018 by the OSIRIS-REx spacecraft from a range of 24 kilometers. PICTURE: NASA/Goddard/University of Arizona/Handout via Reuters
The Potential Impact
A collision with Bennu would be disastrous. Immediate destruction aside, such an event would inject 100 to 400 million tons of dust into the Earth’s atmosphere, causing prolonged climate disruptions and environmental changes.
According to Lan Dai, a postdoctoral research fellow at the IBS Center for Climate Physics at Pusan National University in South Korea and lead author of the study published in the journal Science Advances, the dust would cause a global “impact winter” characterized by reduced sunlight, colder surface temperatures, and decreased precipitation.
In the worst-case scenario, Earth’s average surface temperature could drop by four degrees Celsius, rainfall could decrease by 15 percent, and photosynthesis could be reduced by 20-30 percent. The ozone layer could also deplete by 32 percent, exacerbating the harmful effects of solar ultraviolet radiation.
Secondary Effects and Long-Term Impacts
The impact would generate a powerful shockwave, earthquakes, wildfires, and thermal radiation, as well as create a large crater and eject significant debris into the atmosphere. Large quantities of aerosols and gases would significantly affect weather patterns and ecosystems for years.
These unfavorable conditions would impede plant growth on both land and in the ocean. On land, plants would take two years to recover, while plankton in the ocean would show resilience, potentially increasing with diatom blooms triggered by the influx of iron-rich dust.
The Human Factor
The potential human casualties from an asteroid strike of this magnitude are staggering, although the exact toll would depend on where the asteroid hit. The study did not address this aspect, leaving researchers to speculate that impacts near densely populated areas could result in unprecedented loss of life.
Scientific Insights from Bennu
Despite the looming threat, studying Bennu has proven invaluable for scientific research. In January 2023, a study showed that the samples collected by NASA’s OSIRIS-REx spacecraft contained some of the fundamental building blocks of life. This discovery strengthens the theory that asteroids may have brought early Earth the necessary ingredients for the development of life.
Asteroids: A Past and Future Threat
Asteroids have periodically collided with Earth throughout its history, often with devastating consequences. The most famous example is the asteroid that struck the Yucatan Peninsula 66 million years ago, leading to the extinction of the dinosaurs and approximately three-quarters of all species.
Recognizing this, NASA conducted a landmark proof-of-principle planetary defense mission in 2022. Using the robotic DART spacecraft, they successfully altered the trajectory of the asteroid Dimorphos, aiming to prepare for similar situations in the future.
The Importance of Preparedness
While the chance of Bennu striking Earth is low, at only 0.037 percent, the potential consequences are grave. Such an impact could result in significant long-term food insecurity and climate changes akin to those caused by some of the largest volcanic eruptions in the last 100,000 years.
“So it is important to think about the risk,” Axel Timmermann, a climate physicist and senior author of the study, emphasized.
We rely on our readers to fund Sight’s work – become a financial supporter today!
Your support helps us continue delivering in-depth, reliable news and analysis. Thank you for your generosity.
Join the conversation, share your thoughts, and stay informed!
To learn more about our ongoing projects and future endeavors, consider subscribing to our newsletter. Your subscription will keep you updated on the latest developments in space exploration and other fields.
Don’t forget to share this article on your social media platforms to spread awareness about the fascinating and sometimes threatening world beyond Earth.
Your support and engagement mean the world to us. Thank you for being a part of the Archynetys community.
Join us now and be part of a bright and informed future!
Subscribe to Archynetys Newsletter
Share on Facebook | Share on Twitter | Share on LinkedIn