Ancient meteor may have caused life on Earth, study finds

An ancient meteorite that crashed to Earth billions of years ago may have created the first lifeforms, a study claims. 

The S2 meteorite which was 200 times bigger than the one that caused dinosaurs to become extinct is believed to have struck South Africa 3.26 billion years ago.

Researchers at Harvard University reported that there is still evidence of the meteor's impact in an area called the Barberton Greenstone Belt in southeastern Africa.

Despite the previously held belief that meteorites of this size completely decimated all lifeforms, by analyzing rock samples the researchers found that in this case it may have helped rebuild life on Earth.

In the aftermath of the crash, massive tsunamis pushed debris from the land into the ocean which stirred up iron from the seafloor.

When combined with the phosphorous from the S2 meteorite, the collision created ideal conditions for bacteria to thrive.

Nadja Drabon, an early-Earth geologist at Harvard University and the study's lead author said: 'We think of impact events as being disastrous for life.

'But what this study is highlighting is that these impacts would have had benefits to life, especially early on … these impacts might have actually allowed life to flourish.'

Researchers studied rock residue from the Barberton Greenstone Belt which is known for being one of the oldest and most well-preserved pieces of continental crust.

It's located on the eastern edge of the Kaapvaal Craton which was once part of a supercontinent called Vaalbara that existed from 3.6 to 2.2 billion years ago before splitting into two separate continents.

The team collected 214 samples of rock from 16 feet beneath where S2 hit to 26 feet above the location in an area called Bruce's Hill and Umbaumba.

They analyzed 83 samples for major, trace and rare earth elements while other portions were analyzed for organic carbon isotopes which can be used to trace the object's origin and history.

Through their findings, Harvard University researchers were able to construct what happened when the meteor struck. 

When the S2 meteorite - which was quadruple the size of Mount Everest - crashed into Earth, it created a series of events that spurred the formation of bacteria and the possible creation of all life.

After triggering the massive tsunami which carried debris to the sea, the top layer of the ocean started to boil, thus heating the atmosphere and creating a thick cloud of dust that blocked out all sunlight.

Picture yourself standing off the coast of Cape Cod, in a shelf of shallow water. It's a low-energy environment, without strong currents,' Drabon said.

'Then all of a sudden, you have a giant tsunami, sweeping by and ripping up the seafloor.'

This effectively halted photosynthesis - the process used by plants, algae and some bacteria to convert water and carbon dioxide into oxygen using sunlight.

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Despite this, researchers found that the impact caused the land to erode and stirred up iron from deep in the ocean and allowed iron-metabolizing bacteria to proliferate.

Even though the impact was likely short-lived, their findings represent a key development in understanding how life began. 

There are records of at least 16 major events involving extremely bright meteors that impacted Earth and had severe consequences for the environment but their impact on early life still isn't fully understood, the study said.

'The environmental effects of the S2 meteorite impact, and probably other large early Archean impacts, appear to have had mixed effects on early marine life,' it continued. 

'Some forms of life were positively impacted while others faced increased challenges,' like the one that wiped out the dinosaurs.

The researchers concluded: 'Our work suggests that on a global scale, early life may have benefitted from an influx of nutrients and electron donors, as well as new environments, as a result of major impact events.'