Massive Asteroid Worked Like 'Fertilizer Bomb' for Early Life

Sixty-six million years ago, a large asteroid struck Earth. It sent plumes of soot and ash into the sky that blocked out the sun. The fallout led to the extinction of many forms of life on Earth. That includes most of the dinosaurs. New research shows, though, that an earlier asteroid had the opposite effect on life on Earth.

The 23- to 36-mile-wide asteroid was 200 times the size of the one that wiped out the dinosaurs. It slammed into the planet 3.26 billion years ago. The result was as earth-shattering as one might expect.   

"The effects of the impact would have been quick and ferocious,” Harvard geologist Nadja Drabon told Reuters. She is the author of the study published this month in Proceedings of the National Academy of Sciences. “The impact likely occurred in the ocean." That, Drabon noted, would have sent a tsunami across the globe. She added, "A lot of the impact energy would get transferred into heat." It would have been so hot that the oceans would have been boiling at points, she said.  

Drabon’s team learned about the asteroid by looking at minerals in the soil of South Africa. There, they found traces of the impact in the thin layers of the Earth’s crust.  

The asteroid’s effects would cause a mass extinction event if it struck Earth today. But 3 billion years ago, the only life on Earth was bacteria and other single-celled organisms. They managed to recover quickly. And the massive asteroid brought with it an ample supply of phosphorus and iron. Those two elements are needed for growing more complicated life forms. 

"Imagine these impacts to be giant fertilizer bombs," Drabon told Reuters.        

Reflect: How do you think scientists figure out the impact of events from millions of years ago?

Photo of an asteroid from Unsplash courtesy of NASA Hubble Space Telescope.