NASA simulation shows a large moon-sized planetary body penetrating all the way down to the Earth’s core. An ancient massive collision.
Simone Marchi of the Southwest Research Institute in Colorado, US, together with its team used a computational method to simulate a violent period of the Earth’s life immediately following the formation of the moon.
4.5 billion years ago, a planet with the size of Mars smashed into Earth. This impact threw the debris out, hence, started to rotate around Earth. Gradually, the clumping together of debris formed our moon.
Bombardment by leftover object
After the Moon’s formation, Earth experienced a bombardment by leftover objects which continued for thousands of years. Scientists, collectively call these objects planetesimals.
Leftover rocks varied from the size of a grain of sand to monstrous flying object more than 3000 kilometers across.
Lead author of the paper published in the Nature Geoscience, together with colleagues found evidence of more massive accretion onto the Earth than previously thought after the Moon’s formation.
Research revealed much higher mantle abundances of certain trace elements such as platinum, iridium, and gold than what scientists would expect to result from core formation. These elements tend to bond chemically with metallic iron.
The researching team found the total amount of material delivered to Earth may have been 2-5 times greater than previously thought. Also, the impacts altered Earth in a profound way while depositing familiar elements like gold.
“These results have far-reaching implications for Moon-forming theories and beyond,” said Marchi. “Interestingly, our findings elucidate the role of large collisions in delivering precious metals like gold and platinum found here on Earth.”
The modeling showed that in many cases the planetesimals would not have broken upon or near the surface. Instead, the elements would have punched right through the Earth’s mantle. They kept going until they hit the planet’s own core, adding to its mass.
Thumbnail image: An artist’s impression of a large collision on the early Earth. Credit: SWRI / MARCHI