Meteorite 100 times larger than dinosaur-killing space rock
Recent study reveals that a massive meteorite impact on early Earth may have allowed life to flourish.
A 3.26 billion-year-old impact site suggests that microbial life, the only sort of life at the period, may have benefited from a meteorite 50 to 200 times larger than the one that killed the nonavian dinosaurs.
Drabon and her colleagues explored an Archean eon (4 billion to 2.5 billion years ago) influence in South Africa. This was a shallow sea then. Drabon told Live Science that rocks this old record a moment in such detail in few places on Earth.
Researchers found spherules, tiny glass-like spheres formed when a meteorite melts silica-containing rock, in the strata. Some see conglomerates, or rocks formed of other rocks.
A global tsunami ripped up the seafloor and clumped the debris into conglomerates. The meteor, a carbonaceous chondrite, is preserved in the rock strata' chemistry. About 23 to 36 miles (37 to 58 kilometers) in diameter.
Even though South Africa was far from the impact, the collision had tremendous ramifications. It caused a global tsunami and blew dust that would have blocked the sun. Evaporated minerals reveal the impact heated the atmosphere sufficiently to boil the ocean's upper layers.
Within years or decades of the effect, life returned, possibly better than before. The study authors found that post-impact, life-sustaining components spiked.
First was phosphorus, a vital mineral that may have been scarce in the waters 3.26 billion years ago. Today, phosphorous erodes from continental rocks into the oceans, but during the Archean, Earth was primarily water with a few volcanic islands and small continents.