Meteorite Strike Sparked Life on Early Earth Billions of Years Ago

A meteorite that struck Earth three billion years ago may have laid the groundwork for life to flourish on the planet, according to a team of scientists. However, this event initially caused widespread devastation.

The meteorite, discovered in 2014, was 200 times larger than the asteroid that wiped out the dinosaurs 66 million years ago. At the time of impact, Earth was mostly covered in oceans, with only a few landmasses scattered across the surface. The collision generated intense heat, boiling the oceans and creating what is believed to be the largest tsunami in Earth’s history.

The research team made three expeditions to the Eastern Barberton Greenbelt in South Africa, one of the oldest places on Earth where evidence of the meteorite’s impact can still be observed.

This meteorite, named S2, was part of the debris orbiting Earth after its formation. S2 was 40-60 kilometers wide, with a mass 50-200 times greater than the asteroid that killed the dinosaurs, which was about 10 kilometers wide, comparable to the size of Mount Everest.

Professor Nadja Drabon of Harvard University, the lead author of the study, explained, “We know that after Earth first formed, there was still a lot of debris flying around space that would collide with the planet. But we now understand that life proved to be incredibly resilient after some of these enormous impacts, and it even thrived.”

At that time, Earth hosted simple microorganisms, primarily single-celled organisms. Prof. Drabon and her team collected hundreds of kilograms of rock from the impact site and analyzed them in the lab, searching for tiny rock fragments left behind by the meteorite.

Their findings indicate that the meteorite created a crater 500 kilometers wide and shattered the surrounding rocks. The debris from the impact moved at high speeds, forming a cloud that encircled the planet. “Imagine a rain cloud,” Drabon explained, “but instead of water droplets, it’s molten rock raining down from the sky.”

The collision triggered a tsunami that disrupted the seafloor, while the heat evaporated large amounts of ocean water and raised air temperatures by up to 100 degrees Celsius. The impact was so severe that it darkened the skies, preventing sunlight from reaching the surface and wiping out life dependent on photosynthesis.

Yet, in the aftermath of the devastation, nutrients like phosphorus and iron were stirred up, which helped life bounce back rapidly. The tsunami brought iron-rich water from the ocean’s depths to the surface, providing early microbes with an abundance of energy.

Prof. Drabon remarked, “Life was not only resilient but rebounded remarkably quickly and flourished.” She added that the research supports the idea that early life on Earth may have benefited from other meteorite impacts during the planet’s formative years.