Killer asteroids were a regular occurrence in the early days of Earth
What does an awesome slow-motion video of a ball falling into sand have to do with any of that? BOOM. That’s what.
Around 65 million years ago, an asteroid about six miles across struck the Earth, incinerating the local atmosphere and leading to mass extinction of the dinosaurs. New research from NASA geologists suggests that between 1.8 and 3.8 billion years ago, perhaps seventy such impacts occurred.
In the early solar system, the gas giant planets like Jupiter and Neptune hadn’t quite settled into their homes at the outer reaches of our planetary neighborhood. Their irregular orbits sent enormous hunks of debris hurtling toward young Earth (an era called the Late Heavy Bombardment). If you were an early single-celled organism on Earth, just chillin in your mineral pool, minding your own prokaryotic business, life would have been very eventful, and destructive.
By locating the debris patterns in deep rock that occur with impacts such as these, followed by plugging them into an advanced computer model, these researchers guess that “dino-killer” type asteroids may have been a regular event.
I wonder how they might have shaped early evolution? Thank goodness the solar system has settled down a bit since then.
Previously: For more awesome Late Heavy Bombardment boom-booms, check out this video reconstruction of the Moon’s evolution, and check out my answer about where our moon’s particular crater pattern came from.
Source: earthsky.org
