A Greater Sudbury man is reflecting on his once-in-a-lifetime contribution to a groundbreaking space mission that mapped the Bennu asteroid, a celestial object scientists say has a slim chance of colliding with Earth in 2182.
James Dorland, a second-generation land surveyor, was invited to help calibrate an instrument used to measure and map the size of Bennu. The project was based on samples collected by NASA’s OSIRIS-REx spacecraft, which retrieved roughly 121 grams of material from the asteroid in 2020.
For Dorland, the opportunity was a dream come true, he said.
“The gravity of it was apparent to me,” said Dorland.
“It was an opportunity I could not turn down.”
The Canadian contribution to the mission involved a light sensor used to map the asteroid’s topography. This detailed map was critical in selecting a landing site for the spacecraft to collect samples.
“It’s once in a lifetime, right? I grew up wanting to be Spock on Star Trek, and so I have a soft spot for science,” said Dorland.
Asteroid Bennu’s potential threat
Scientists estimate that Bennu, a near-Earth asteroid, has a 1 in 2,700 chance of colliding with Earth in September 2182. While the probability is low, the potential consequences of such an impact are severe.
Bennu, classified as a “rubble pile” asteroid, is a loose collection of rocky material rather than a solid object. It is a remnant of a larger celestial body formed roughly 4.5 billion years ago, near the dawn of the solar system.
According to recent research, an impact by an asteroid of Bennu’s size – approximately 500 meters in diameter – would cause immediate devastation, including a powerful shockwave, earthquakes, wildfires and a massive crater. The long-term effects could be even more catastrophic.
A study, published in the journal Science Advances, estimates that such an impact would inject 100-400 million tons of dust into the atmosphere, triggering an “impact winter.” This phenomenon would reduce sunlight, lower global temperatures by up to 4 degrees Celsius and decrease precipitation by 15%. The resulting climate disruptions could last three to four years – severely affecting global agriculture and ecosystems.
“The solar dimming due to dust would cause an abrupt global ‘impact winter,’ characterized by reduced sunlight, cold temperatures and decreased precipitation at the surface,” said Lan Dai, the study’s lead author and a postdoctoral research fellow at the IBS Center for Climate Physics in South Korea.
The study also predicts a 32 per cent depletion of the ozone layer, which protects Earth from harmful ultraviolet radiation. While ocean plankton could recover within six months, land plants would face a slower recovery, potentially leading to food insecurity.
Asteroid impacts in Earth’s history
Asteroid impacts have shaped Earth’s history, with the most famous example being the asteroid that struck Mexico’s Yucatan Peninsula 66 million years ago, wiping out the dinosaurs.
Bennu’s potential impact would not be on the same scale, it could still cause significant loss of life and long-term environmental damage.
NASA’s OSIRIS-REx mission has provided invaluable insights into Bennu’s composition. A study published earlier this year revealed that the asteroid contains chemical building blocks of life, supporting the theory that asteroids may have seeded early Earth with the ingredients necessary for life to emerge.
Experts call for the world to be prepared
In 2022, NASA demonstrated the potential to deflect asteroids with its DART mission, which successfully altered the trajectory of the asteroid Dimorphos – such efforts could prove crucial if an asteroid like Bennu were ever found to be on a collision course with Earth.
While the likelihood of Bennu striking Earth remains low, scientists emphasize the importance of preparedness.
“Even though small, the potential impact would be very serious,” said Axel Timmermann, a climate physicist and co-author of the Science Advances study.
“It is important to think about the risk.”
For James Dorland, his involvement in mapping Bennu was not just a professional achievement but a personal milestone – calling it “humbling” to think about.
With files from Reuters' Will Dunham
