A meteorite 100 times bigger than the dinosaur-killing space rock may have nourished early microbial life

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New research suggests that the massive destruction caused by a giant meteorite hitting early Earth may have actually set the stage for life to thrive.

Researchers found that the immediate devastation caused by the impact was followed by the release of essential nutrients from the meteorite and a resulting tsunami, which were vital for the survival of microbes.

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Drabon and her colleagues studied evidence of an impact that occurred during the Archean eon (4 billion to 2.5 billion years ago) in what is now South Africa. At that time, this area was a shallow sea environment. There are likely only a few places on Earth where rocks from that era preserve a moment in such detail, Drabon said to Live Science.

In the layers, researchers can spot tiny, glass-like globules known as spherules that form when a meteorite impact melts silica-containing rock. They also notice conglomerates, which are rocks made up of other pieces of rock. The conglomerates indicate a massive, globe-encompassing tsunami that tore up the seafloor and compacted the debris into clumps. The chemistry of the rock layers shows remnants of the meteor itself, which was a primitive type of space rock called a carbonaceous chondrite. It's estimated that the meteor would have measured between 23 and 36 miles (37 to 58 kilometers) in diameter.

Impact evidence shows that the impact also heated the atmosphere to the point of boiling the upper layers of the ocean.

"It would have been extremely catastrophic for any life on land or in shallow water," Drabon said.

In a few years or decades after the impact, though, life started coming back, and it might have even been in better shape than before. The study authors pointed out that, following the impact, there was a sudden surge in the levels of elements that are crucial for life.

The planet was mostly a water-covered world, with only a few volcanic islands and small continents. A carbonaceous chondrite of the impactor's size would have carried hundreds of gigatons of phosphorus, Drabon said.

The second element was iron, which would have been abundant in the deep Archean oceans but scarce in the shallow seas. However, the tsunami triggered by the meteorite impact would have mixed the oceans, bringing this metal into shallower regions, Drabon explained. The red rocks found in the layers above the impact site indicate this shift in the environment.

The study sheds light on how life began to thrive on a young planet that was frequently battered by massive space collisions. The geological record indicates that large meteorites, such as the one that wiped out the dinosaurs, struck the early Earth at least once every 15 million years. Life was adaptable, Drabon noted, but these impacts may have influenced life's development each time they occurred.

"The extinction of the dinosaurs gave mammals a chance to thrive, and who knows if we'd be here today without it," Drabon said. The massive impacts that occurred during the Archean era may have had a significant impact on the types of microbes that survived and the ones that went extinct.

"The outcome of any action will have both negative and positive consequences," Drabon said.