According to a new study, huge asteroids such as those that caused the extinction of dinosaurs crashed into the young Earth more often than expected, writes Space.com. According to researchers, our developing planet is hit by a city-sized or even larger object every 15 million years.
During the period of violence 2.5-3.5 billion years ago, the Earth has changed a lot, and traces of transformations can still be seen in the rocks. Simone Marchi, a colleague and colleagues at the Southwest Research Institute in Boulder analyzed the so-called spherols, which are tiny bubbles formed from evaporated rocks by impact. Due to the collisions, the materials went into space, where they then solidified again and then fell back to the surface.
Experts used a model to assess how asteroids could form spherols and how they could be distributed on the planet. When the researchers compared the traces in the different layers with the known impacts, they found a discrepancy.
These ancient events also affected oxygen levels and thus may even have affected the development of life.
On some rare atmospheric objects, such as the moon, traces of former collisions are fairly well discernible, but on Earth, due to geological activity and weather patterns, the evidence easily disappears. The new discovery confirms that we still have a lot to learn from the great bumps of the past.
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