Scientists Predict Devastation if Asteroid Bennu Strikes Earth in 2182

FILE - This May 18, 1969 photo provided by NASA shows Earth from 36,000 nautical miles away as photographed from the Apollo 10 spacecraft during its trans-lunar journey toward the moon. (NASA via AP)
FILE - This May 18, 1969 photo provided by NASA shows Earth from 36,000 nautical miles away as photographed from the Apollo 10 spacecraft during its trans-lunar journey toward the moon. (NASA via AP)
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Scientists Predict Devastation if Asteroid Bennu Strikes Earth in 2182

FILE - This May 18, 1969 photo provided by NASA shows Earth from 36,000 nautical miles away as photographed from the Apollo 10 spacecraft during its trans-lunar journey toward the moon. (NASA via AP)
FILE - This May 18, 1969 photo provided by NASA shows Earth from 36,000 nautical miles away as photographed from the Apollo 10 spacecraft during its trans-lunar journey toward the moon. (NASA via AP)

The rocky object called Bennu is classified as a near-Earth asteroid, currently making its closest approach to Earth every six years at about 186,000 miles (299,000 km) away. It might come even closer in the future, with scientists estimating a one-in-2,700 chance of a collision with Earth in September 2182, Reuters reported.
So what would happen should Bennu strike our planet? Well, it would not be pretty, according to new research based on computer simulations of an impact by an asteroid with a diameter of roughly three-tenths of a mile (500 meters) like Bennu.
Aside from the immediate devastation, it estimated that such an impact would inject 100-400 million tons of dust into the atmosphere, causing disruptions in climate, atmospheric chemistry and global photosynthesis lasting three to four years.
"The solar dimming due to dust would cause an abrupt global 'impact winter' characterized by reduced sunlight, cold temperature and decreased precipitation at the surface," said Lan Dai, a postdoctoral research fellow at the IBS Center for Climate Physics (ICCP) at Pusan National University in South Korea and lead author of the study published this week in the journal Science Advances.
In the worst-case scenario, the researchers found that Earth's average surface temperature would decrease by about 7 degrees Fahrenheit (4 degrees Celsius), average rainfall would fall by 15%, there would be a reduction of up to 20-30% in plant photosynthesis and a 32% depletion in the planet's ozone layer that protects against harmful solar ultraviolet radiation.
The impact of a Bennu-sized object - a medium-sized asteroid - on Earth's land surface would generate a powerful shockwave, earthquakes, wildfires and thermal radiation, leave a gaping crater and eject huge amounts of debris upward, the researchers said.
Large quantities of aerosols and gases would reach the upper atmosphere, causing years-long effects on climate and ecosystems, according to Dai and study senior author Axel Timmermann, a climate physicist and ICCP director.
The unfavorable climate conditions would inhibit plant growth on land and in the ocean, they said.
"In contrast to the rapid reduction and slow two-year-long recovery of plants on land, plankton in the ocean would recover within six months - and even increase afterward with unprecedented diatom (a type of algae) blooms triggered by iron-rich dust deposition into the ocean," Dai said.
Severe ozone depletion would occur in the stratosphere - the second atmospheric layer as you go upward - due to strong warming caused by the solar absorption of dust particles, the researchers said.
An asteroid collision of this magnitude could cause massive loss of human life, but that calculation was outside the study's scope. Dai said the potential death toll "mainly depends on where the asteroid impact occurs."
Scientists know a great deal about Bennu, considered a "rubble pile" asteroid - a loose amalgamation of rocky material rather than a solid object. It is a rocky remnant of a larger celestial body that had formed near the dawn of the solar system roughly 4.5 billion years ago. NASA's robotic OSIRIS-REx spacecraft journeyed to Bennu and in 2020 collected samples of rock and dust for analysis.
A study published in January showed that Bennu's samples bore some of the chemical building blocks of life, strong evidence that asteroids may have seeded early Earth with the raw ingredients that fostered the emergence of living organisms.
Asteroids have struck Earth occasionally over its long history, often with cataclysmic results. An asteroid estimated at 6-9 miles (10-15 km) wide hit off the coast of Mexico's Yucatan Peninsula 66 million years ago, eradicating about three-quarters of the world's species and ending the age of dinosaurs.
NASA in 2022 carried out a proof-of-principle planetary defense mission by using its robotic DART spacecraft to change the trajectory of the asteroid Dimorphos, with an eye toward doing this in the future if one appears on a collision course with Earth.
"The likelihood that a Bennu-sized asteroid will strike Earth is quite small at 0.037%. Even though small, the potential impact would be very serious and would likely lead to massive longer-term food insecurity on our planet and climate conditions that are similar to those seen only for some of the largest volcanic eruptions in the last 100,000 years," Timmermann said.
"So it is important to think about the risk," Timmermann added.



NASA Astronauts Return to Earth after Drawn-out Mission in Space

Support teams work around a SpaceX Dragon spacecraft shortly after it landed with NASA astronauts Nick Hague, Suni Williams, Butch Wilmore, and Roscosmos cosmonaut Aleksandr Gorbunov aboard in the water off the coast of Tallahassee, Florida, USA, 18 March 2025. EPA/NASA/Keegan Barber
Support teams work around a SpaceX Dragon spacecraft shortly after it landed with NASA astronauts Nick Hague, Suni Williams, Butch Wilmore, and Roscosmos cosmonaut Aleksandr Gorbunov aboard in the water off the coast of Tallahassee, Florida, USA, 18 March 2025. EPA/NASA/Keegan Barber
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NASA Astronauts Return to Earth after Drawn-out Mission in Space

Support teams work around a SpaceX Dragon spacecraft shortly after it landed with NASA astronauts Nick Hague, Suni Williams, Butch Wilmore, and Roscosmos cosmonaut Aleksandr Gorbunov aboard in the water off the coast of Tallahassee, Florida, USA, 18 March 2025. EPA/NASA/Keegan Barber
Support teams work around a SpaceX Dragon spacecraft shortly after it landed with NASA astronauts Nick Hague, Suni Williams, Butch Wilmore, and Roscosmos cosmonaut Aleksandr Gorbunov aboard in the water off the coast of Tallahassee, Florida, USA, 18 March 2025. EPA/NASA/Keegan Barber

NASA astronauts Butch Wilmore and Suni Williams returned to Earth in a SpaceX capsule on Tuesday with a soft splashdown off Florida's coast, nine months after their faulty Boeing Starliner craft upended what was to be a week-long stay on the International Space Station.
Their return caps a protracted space mission that was fraught with uncertainty and technical troubles, turning a rare instance of NASA's contingency planning - and the latest failures of Starliner - into a global and political spectacle, Reuters reported.
Wilmore and Williams, two veteran NASA astronauts and retired US Navy test pilots, had launched into space as Starliner's first crew in June for what was expected to be an eight-day test mission. But issues with Starliner's propulsion system led to cascading delays to their return home, culminating in a NASA decision to fold them into its crew rotation schedule and return them on a SpaceX craft this year.
On Tuesday morning, Wilmore and Williams strapped inside their Crew Dragon spacecraft along with two other astronauts and undocked from the ISS at 1.05 a.m. ET (0505 GMT) to embark on a 17-hour trip to Earth.
The four-person crew, formally part of NASA's Crew-9 astronaut rotation mission, plunged through Earth's atmosphere, using its heatshield and two sets of parachutes to slow its orbital speed of 17,000 mph (27,359 kph) to a soft 17 mph at splashdown, which occurred at 5:57 p.m. ET some 50 miles off Florida's Gulf Coast under clear skies.
"What a ride," NASA astronaut Nick Hague, the Crew-9 mission commander inside the Dragon capsule, told mission control moments after splashing down. "I see a capsule full of grins, ear to ear."
The astronauts will be flown on a NASA plane to their crew quarters at the space agency's Johnson Space Center in Houston for a few days of routine health checks before NASA flight surgeons say they can go home to their families.
"They will get some well-deserved time off, well-deserved time with their families," NASA's Commercial Crew Program chief Steve Stich told reporters after the splashdown. "It's been a long time for them."
POLITICAL SPECTACLE
The mission captured the attention of US President Donald Trump, who upon taking office in January called for a quicker return of Wilmore and Williams and alleged, without evidence, that former President Joe Biden "abandoned" them on the ISS for political reasons.
NASA acted on Trump's demand by moving Crew-9's replacement mission up sooner, the agency's ISS chief Joel Montalbano said Tuesday. The agency had swapped a delayed SpaceX capsule for one that would be ready sooner and sped through its methodical safety review process to heed the president's call.
Trump told Fox News on Tuesday that Wilmore and Williams will visit the Oval Office after they recover from their mission.
Wilmore earlier this month told reporters on a call from the ISS that he did not believe NASA's decision to keep them on the ISS until Crew-10's arrival had been affected by politics under the Biden administration.
SpaceX CEO Elon Musk, a close adviser to Trump, had echoed Trump's call for an earlier return, adding the Biden administration spurned a SpaceX offer to provide a dedicated Dragon rescue mission last year.
NASA officials have said the two astronauts had to remain on the ISS to maintain adequate staffing levels and it did not have the budget or the operational need to send a dedicated rescue spacecraft. Crew Dragon flights cost between $100 million to $150 million.
Crew Dragon is the only US spacecraft capable of flying people in orbit. Boeing had hoped Starliner would compete with the SpaceX capsule before the mission with Wilmore and Williams threw its development future into uncertainty.
Stich said on Tuesday that Starliner might need to fly another uncrewed flight - which would be its third such mission and fourth test overall - before it routinely carries US astronauts.
Boeing, which congratulated the astronauts' return on X, did not respond immediately to a request for comment.
286 DAYS IN SPACE
The ISS, about 254 miles in altitude, is a football field-sized research lab that has been housed continuously by international crews of astronauts for nearly 25 years, a key platform of science diplomacy managed primarily by the US and Russia.
Swept up in NASA's routine astronaut rotation schedule, Wilmore and Williams worked on roughly 150 science experiments aboard the station until their replacement crew launched last week.
The pair logged 286 days in space on the mission - longer than the average six-month ISS mission length, but far short of US record holder Frank Rubio, whose 371 days in space ending in 2023 were the unexpected result of a coolant leak on a Russian spacecraft.
Living in space for months can affect the human body in multiple ways, from muscle atrophy to possible vision impairment.
Williams, capping her third spaceflight, has tallied 608 cumulative days in space, the second most for any US astronaut after Peggy Whitson's 675 days. Russian cosmonaut Oleg Kononenko set the world record last year at 878 cumulative days.
"We came prepared to stay long, even though we planned to stay short," Wilmore told reporters from space earlier this month.
"That's what your nation's human spaceflight program's all about," he said. "Planning for unknown, unexpected contingencies. And we did that."