A giant asteroid, S2, which smashed into Earth 3.26 billion years ago may have actually helped life flourish, rather than snuffing it out, according to a recent study by a team of geologists.
The asteroid impact was first discovered in 2014.
It’s thought that the space rock was initially around 40 to 60km (25 to 37 miles) wide, giving it a mass as much as 200 times greater than the asteroid that killed the dinosaurs.
A team of geologists, led by Nadja Drabon from Harvard University, investigated the impact by painstakingly gathering samples from the Barberton Greenstone belt of South Africa.
The team used hammers and chisels to collect rock samples a few inches apart, then examining them to analyse the sedimentary layers which were laid down before, during and after the asteroid impact, S2, building a timeline of events.
How did asteroid S2 affect life on Earth?
This revealed that the meteor generated enough heat that the surface layer of the ocean boiled away, releasing a huge amount of heat into the atmosphere.
The shock of the impact created a huge tsunami, stirring up sediment from the bottom of the ocean.
“Picture yourself standing off the coast of Cape Cod, in a shelf of shallow water. It’s a low-energy environment, without strong currents. Then all of a sudden, you have a giant tsunami sweeping by and ripping up the sea floor,” says Drabon.
As the water raced across the landscape, it would have similarly torn up the suface. When the wave then receded, all this ravaged material would then be deposited across the landscape.
This destruction would have decimated any large fauna living on the planet.
Fortunately three billion years ago when the impact occurred, Earth was mostly populated by single celled organisms which are much hardier and quickly recovered.
In fact, Drabon’s team found evidence of a spike in organisms that feed on iron and phosphorous, indicating that the asteroid impact S2 actually helped some forms of life on Earth.
These were probably feeding on iron stirred up from the ocean or excavated from the land by the tidal wave.
“We think of impact events as being disastrous for life,” says Drabon. “But what this study is highlighting is that these impacts would have had benefits to life, especially early on, and these impacts might have actually allowed life to flourish.”
